HESI A2 CHEMISTRY FILES

Chemistry

1. What are all metric measurements composed of?

A. Metric prefix and a basic unit of measure

B. A significand and a metric prefix

C. A metric prefix and a coefficient

D. A coefficient and a significand

2. What is the most commonly used temperature scale in the scientific community?

A. Fahrenheit

B. Celsius or Centigrade

C. Kelvin

D. English temperature method

3. The nucleus of an atom contains or is made up of which of the following?

A. Protons and electrons

B. Protons only

C. Protons and neutrons

D. Neutrons and electrons

4. What is an atom that has a positive charge called?

A. A cathode

B. A cation

C. An anode

D. An anion

5. In the periodic table, what are the rows called?

A. Groups

B. Moles

C. Columns

D. Periods

6. What is the atomic number?

A. Number of neutrons

B. Number of protons

C. Number of electrons

D. Number of isotopes

7. Which of the following describes the atomic mass?

A. Mass of protons and electrons

B. Mass of neutrons and electrons

C. Average mass of that element’s isotopes

D. Number of moles in a solution

8. Chemical equations are written in which manner?

A. Product → Reactants

B. Reactants → Products

C. Reactants + Reactants

D. Products + Reactants

9. What is the charge on potassium in the compound KCl?

A. −1

B. +1

C. −2

D. +2

10. A catalyst is a substance that accelerates a reaction by which of the following?

A. Adding energy to the overall reaction

B. Increasing the amount of energy needed for the reaction to occur

C. Finding an alternate pathway for a reaction that requires less energy

D. Speeding up the overall reaction process

11. Percent concentration of a solution is expressed as which of the following?

A. 100 parts per 100 dL

B. Parts per 100 parts

C. Parts of moles

D. Moles per 100 parts

12. What will one liter of a one molar solution of any element contain?

A. The atomic mass in grams of that element

B. The atomic number in grams of that element

C. The atomic mass in liters of that element

D. The atomic number in liters of that element

13. Chemical bonding is the bonding of which of the following?

A. One atom to another atom

B. One mole to another mole

C. A proton to an electron

D. One cation to another cation

14. Which of the following describes an ionic bond?

A. It shares electrons.

B. It does not share electrons.

C. It is sometimes called a covalent bond.

D. It is the strongest of all chemical bonds.

15. The reaction 2C2H6 + 7O2 → 4CO2 + 6H2O has a ratio of 2 parts ethane (C2H6) and 7

parts oxygen (O2). How many parts of ethane (C2H6) will be needed to react with 21 parts of

oxygen (O2)?

A. 3 parts of ethane C2H6

B. 6 parts of ethane C2H6

C. 9 parts of ethane C2H6

D. 14 parts of ethane C2H6

16. What is the concentration of 58.5 g of NaCl in 2 L of solution (atomic weights of each

element are as follows: Na = 23 g/mol, Cl = 35.5 g/mol)?

A. 0.5 mol NaCl

B. 0.75 mol NaCl

C. 1 mol NaCl

D. 2 mol NaCl

17. In a redox reaction, which of the following describes reduction?

A. It is the loss of electrons.

B. It is the gain of protons.

C. It is the loss of a neutron.

D. It is the gain of electrons.

18. What are acids?

A. Hydrogen acceptors

B. Solutions of high pH

C. Hydrogen donors

D. Amphoteric

19. What is a benefit of water’s ability to make hydrogen bonds?

A. Lack of cohesiveness

B. Low surface tension

C. Use as a nonpolar solvent

D. High specific heat

20. What are bases or alkaline solutions?

A. Hydrogen acceptors

B. Solutions of low pH

C. Hydrogen donors

D. Amphoteric

21. Chemical reactions in living systems proceed along catabolic pathways, and there tends

to be an increase in which of the following?

A. Entropy

B. Enthalpy

C. Glucose

D. Glycogen

22. What is a pH of 7?

A. Acidic

B. Basic

C. Neutral

D. Positive

23. Which is the correct way to write Iodine (I) with an atomic mass of 131?

A. I131

B. I131

C. 131I

D. 131I

24. What is the correct formula for magnesium chloride?

A. MgCl2

B. MgCl

C. Mg2Cl

D. Mg2Cl2

25. What is the weakest of all the intermolecular forces?

A. Dispersion

B. Dipole interactions

C. Hydrogen bonding

D. Covalent bonding

26. Beta radiation is the emission of which of the following?

A. Large numbers of helium ions

B. An electron

C. High energy electromagnetic radiation

D. A product of the decomposition of a proton

27. Which of the following describes carbohydrates?

A. They serve as fuel for the body.

B. They are present in DNA but not in RNA.

C. They are the least abundant biomolecule.

D. They cannot be stored in the body.

28. What are monosaccharides?

A. The simplest form of carbohydrates

B. The most complex form of carbohydrates

C. One form of a very complex fat

D. Artificial sweeteners such as saccharin

29. Disaccharides are the joining together of which of the following?

A. Three to six monosaccharides

B. Two monosaccharides

C. A number of monosaccharides

D. A fat and a monosaccharide

30. Glycolysis is one of the body’s chemical pathways for which of the following?

A. Manufacturing glycogen

B. Building proteins

C. Producing fats

D. Metabolizing glucose

31. Amino acids are the building blocks for which of the following?

A. Nucleic acids

B. Carbohydrates

C. Proteins

D. Lipids

32. What is the union of two amino acids using a peptide bond called?

A. A dipeptide

B. A peptide

C. A monopeptide

D. A polypeptide

33. Which of the following describes lipids?

A. They are a major source of fuel for the body immediately after a meal.

B. They are stored for a source of fuel after carbohydrate depletion.

C. They are comprised of glycerol and three fatty acids.

D. They are metabolized by a pathway called glycolysis.

34. Which of the following describes DNA?

A. It is made of two strands of a ribose sugar-phosphate chain.

B. It consists of two strands of a deoxyribose sugar-phosphate chain.

C. It consists of one strand of a ribose sugar-phosphate chain.

D. It is located solely in the mitochondria of individual cells.

35. Use of the periodic table allows prediction of which of the following?

A. The properties of each of the elements

B. The charge of polyatomic ions

C. The number of isotopes in each element

D. The potential for discovery of new elements

36. How could water be boiled at room temperature?

A. By lowering the pressure

B. By increasing the pressure

C. By decreasing the volume

D. By raising the boiling point

37. What is a combustion reaction?

A. It is endothermic.

B. It substitutes one element for another.

C. It always shares electrons.

D. It is a reaction that involves oxygen.

38. What is KCl → K + Cl2 an example of?

A. Synthesis

B. Decomposition

C. Single replacement

D. Double replacement

39. Iodine and carbon dioxide undergo sublimation at room temperature and atmospheric

pressure. What is this process?

A. Changing from a gas to a solid

B. Changing from a liquid to a gas

C. Changing from a solid to a liquid

D. Changing from a solid to a gas

40. An experiment is performed to measure the temperature of boiling water at sea level. The

actual boiling point is 104.6° C, 104.5° C, and 104.4° C. What term best describes these data?

A. Accurate

B. Precise

C. Variable

D. Equivalent

Chemistry Questions with Answers and Explanations

1. Which of the following substances allows for the fastest diffusion?

A. gas

B. solid

C. liquid

D. plasma

Explanation: Diffusion is fastest through gases. The next fastest medium for diffusion is liquid,

followed by plasma, and then solids. In chemistry, diffusion is defined as the movement of

matter by the random motions of molecules. In a gas or a liquid, the molecules are in perpetual

motion. For instance, in a quantity of seemingly immobile air, molecules of nitrogen and oxygen

are constantly bouncing off each other. There is even some miniscule degree of diffusion in

solids, which rises in proportion to the temperature of the substance.

2. What is the oxidation number of hydrogen in CaH2?

A. +1

B. –1

C. 0

D. +2

Explanation: The oxidation number of the hydrogen in CaH2 is –1. The oxidation number is the

positive or negative charge of a monoatomic ion. In other words, the oxidation number is the

numerical charge on an ion. An ion is a charged version of an element. Oxidation number is

often referred to as oxidation state. Oxidation number is sometimes used to describe the number

of electrons that must be added or removed from an atom in order to convert the atom to its

elemental form.

3. Which of the following does not exist as a diatomic molecule?

A. boron

B. fluorine

C. oxygen

D. nitrogen

Explanation: Boron does not exist as a diatomic molecule. The other possible answer choices,

fluorine, oxygen, and nitrogen, all exist as diatomic molecules. A diatomic molecule always

appears in nature as a pair: The word diatomic means “having two atoms.” With the exception of

astatine, all of the halogens are diatomic. Chemistry students often use the mnemonic

BrINClHOF (pronounced “brinkelhoff”) to remember all of the diatomic elements: bromine,

iodine, nitrogen, chlorine, hydrogen, oxygen, and fluorine. Note that not all of these diatomic

elements are halogens.

4. What is another name for aqueous HI?

A. hydroiodate acid

B. hydrogen monoiodide

C. hydrogen iodide

D. hydriodic acid

Explanation: Hydriodic acid is another name for aqueous HI. In an aqueous solution, the solvent

is water. Hydriodic acid is a polyatomic ion, meaning that it is composed of two or more

elements. When this solution has an increased amount of oxygen, the -ate suffix on the first word

is converted to -ic. The HESI exam will require you to know the fundamentals of naming

chemicals. This process can be quite complex, so you should carefully review this material

before your exam.

5. Which of the following could be an empirical formula?

A. C4H8

B. C2H6

C. CH

D. C3H6

Explanation: CH could be an empirical formula. An empirical formula is the smallest

expression of a chemical formula. To be empirical, a formula must be incapable of being

reduced. For this reason, answer choices A, B, and D are incorrect, as they could all be reduced

to a simpler form. Note that empirical formulas are not the same as compounds, which do not

have to be irreducible. Two compounds can have the same empirical formula but different

molecular formulas. The molecular formula is the actual number of atoms in the molecule.

6. What is the name for the reactant that is entirely consumed by the reaction?

A. limiting reactant

B. reducing agent

C. reaction intermediate

D. reagent

Explanation: A limiting reactant is entirely used up by the chemical reaction. Limiting reactants

control the extent of the reaction and determine the quantity of the product. A reducing agent is a

substance that reduces the amount of another substance by losing electrons. A reagent is any

substance used in a chemical reaction. Some of the most common reagents in the laboratory are

sodium hydroxide and hydrochloric acid. The behavior and properties of these substances are

known, so they can be effectively used to produce predictable reactions in an experiment.

7. What is the name for the horizontal rows of the periodic table?

A. groups

B. periods

C. families

D. sets

Explanation: The horizontal rows of the periodic table are called periods. The vertical columns

of the periodic table are known as groups or families. All of the elements in a group have similar

properties. The relationships between the elements in each period are similar as you move from

left to right. The periodic table was developed by Dmitri Mendeleev to organize the known

elements according to their similarities. New elements can be added to the periodic table without

necessitating a redesign.

8. What is the mass (in grams) of 7.35 mol water?

A. 10.7 g

B. 18 g

C. 132 g

D. 180.6 g

Explanation: The mass of 7.35 mol water is 132 grams. You should be able to find the mass of

various chemical compounds when you are given the number of mols. The information required

to perform this function is included on the periodic table. To solve this problem, find the

molecular mass of water by finding the respective weights of hydrogen and oxygen. Remember

that water contains two hydrogen molecules and one oxygen molecule. The molecular mass of

hydrogen is roughly 1, and the molecular mass of oxygen is roughly 16. A molecule of water,

then, has approximately 18 grams of mass. Multiply this by 7.35 mol, and you will obtain the

answer 132.3, which is closest to answer choice C.

9. Which of the following orbitals is the last to fill?

A. 1s

B. 3s

C. 4p

D. 6s

Explanation: Of these orbitals, the last to fill is 6s. Orbitals fill in the following order: 1s, 2s, 2p,

3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, and 7p. The number is the orbital number,

and the letter is the sublevel identification. Sublevel s has one orbital and can hold a maximum of

two electrons. Sublevel p has three orbitals and can hold a maximum of six electrons. Sublevel d

has five orbitals and can hold a maximum of 10 electrons. Sublevel f has seven orbitals and can

hold a maximum of 14 electrons.

10. What is the name of the binary molecular compound NO5?

A. nitro pentoxide

B. ammonium pentoxide

C. nitrogen pentoxide

D. pentnitrogen oxide

Explanation: Nitrogen pentoxide is the name of the binary molecular compound NO5. The

format given in answer choice C is appropriate when dealing with two nonmetals. A prefix is

used to denote the number of atoms of each element. Note that when there are seven atoms of a

given element, the prefix hepta- is used instead of the usual septa-. Also, when the first atom in

this kind of binary molecular compound is single, it does not need to be given the prefix mono-.

11. What is the mass (in grams) of 1.0 mol oxygen gas?

A. 12 g

B. 16 g

C. 28 g

D. 32 g

Explanation: The mass of 1.0 mol oxygen gas is 32 grams. The molar mass of oxygen can be

obtained from the periodic table. In most versions of the table, the molar mass of the element is

directly beneath the full name of the element. There is a little trick to this question. Oxygen is a

diatomic molecule, which means that it always appears in pairs. In order to determine the mass in

grams of 1.0 mol of oxygen gas, then, you must double the molar mass. The listed mass is 16, so

the correct answer to the problem is 32.

12. Which kind of radiation has no charge?

A. beta

B. alpha

C. delta

D. gamma

Explanation: Gamma radiation has no charge. This form of electromagnetic radiation can travel

a long distance and can penetrate the human body. Sunlight and radio waves are both examples

of gamma radiation. Alpha radiation has a 2+ charge. It only travels short distances and cannot

penetrate clothing or skin. Radium and uranium both emit alpha radiation. Beta radiation has a

1– charge. It can travel several feet through the air and is capable of penetrating the skin. This

kind of radiation can be damaging to health over a long period of exposure. There is no such

thing as delta radiation.

13. What is the name of the state in which forward and reverse chemical reactions are

occurring at the same rate?

A. equilibrium

B. constancy

C. stability

D. toxicity

Explanation: When forward and reverse chemical reactions are taking place at the same rate, a

chemical reaction has achieved equilibrium. This means that the respective concentrations of

reactants and products do not change over time. In theory, a chemical reaction will remain in

equilibrium indefinitely. One of the common tasks in the chemistry lab is to find the equilibrium

constant (or set of relative concentrations that result in equilibrium) for a given reaction. In

thermal equilibrium, there is no net heat exchange between a body and its surroundings. In

dynamic equilibrium, any motion in one direction is offset by an equal motion in the other

direction.

14. What is 119°K in degrees Celsius?

A. 32°C

B. –154°C

C. 154°C

D. –32°C

Explanation: 119°K is equivalent to –154 degrees Celsius. It is likely that you will have to

perform at least one temperature conversion on the HESI exam. To convert degrees Kelvin to

degrees Celsius, simply subtract 273. To convert degrees Celsius to degrees Kelvin, simply add

273. To convert degrees Kelvin into degrees Fahrenheit, multiply by 9/5 and subtract 460. To

convert degrees Fahrenheit to degrees Kelvin, add 460 and then multiply by 5/9. To convert

degrees Celsius to degrees Fahrenheit, multiply by 9/5 and then add 32. To convert degrees

Fahrenheit to degrees Celsius, subtract 32 and then multiply by 5/9.

15. What is the SI unit of energy?

A. ohm

B. joule

C. henry

D. newton

Explanation: The joule is the SI unit of energy. Energy is the ability to do work or generate heat.

In regard to electrical energy, a joule is the amount of electrical energy required to pass a current

of one ampere through a resistance of one ohm for one second. In physical or mechanical terms,

the joule is the amount of energy required for a force of one newton to act over a distance of one

meter. The ohm is a unit of electrical resistance. The henry is a unit of inductance. The newton is

a unit of force.

16. What is the name of the device that separates gaseous ions by their mass-to-charge ratio?

A. mass spectrometer

B. interferometer

C. magnetometer

D. capacitance meter

Explanation: A mass spectrometer separates gaseous ions according to their mass-to-charge

ratio. This machine is used to distinguish the various elements in a piece of matter. An

interferometer measures the wavelength of light by comparing the interference phenomena of

two waves: an experimental wave and a reference wave. A magnetometer measures the direction

and magnitude of a magnetic field. Finally, a capacitance meter measures the capacitance of a

capacitor. Some sophisticated capacitance meters may also measure inductance, leakage, and

equivalent series resistance.

17. Which material has the smallest specific heat?

A. water

B. wood

C. aluminum

D. glass

Explanation: Of the given materials, aluminum has the smallest specific heat. The specific heat

of a substance is the amount of heat required to raise the temperature of one gram of the

substance by one degree Celsius. In some cases, specific heat is expressed as a ratio of the heat

required to raise the temperature of one gram of a substance by one degree Celsius to the heat

required to raise the temperature of one gram of water by one degree Celsius.

18. What is the name for a reaction in which electrons are transferred from one atom to

another?

A. combustion reaction

B. synthesis reaction

C. redox reaction

D. double-displacement reaction

Explanation: In a redox reaction, also known as an oxidation-reduction reaction, electrons are

transferred from one atom to another. A redox reaction changes the oxidation numbers of the

atoms. In a combustion reaction, one material combines with an oxidizer to form a product and

generate heat. In a synthesis reaction, multiple chemicals are combined to create a more complex

product. In a double-displacement reaction, two chemical compounds trade bonds or ions and

create two different compounds. Other common chemical reactions you may need to know for

the HESI exam are the acid-base reaction, analysis reaction, single-displacement reaction,

isomerization reaction, and hydrolysis reaction.

19. What are van der Waals forces?

A. the weak forces of attraction between two molecules

B. the strong forces of attraction between two molecules

C. hydrogen bonds

D. conjugal bonds

Explanation: van der Waals forces are the weak forces of attraction between two molecules. The

van der Waals force is considered to be any of the attractive or repulsive forces between

electrons that are not related to electrostatic interaction or covalent bonds. Compared to other

chemical bonds, the strength of van der Waals forces is small. However, these forces have a

great effect on a substance’s solubility and other characteristics. The HESI exam may require

you to demonstrate knowledge of all the major chemical forces.

20. Which of the following gases effuses the fastest?

A. Cl2

B. O2

C. N2

D. H2

Explanation: Of the given gases, H2 effuses the fastest. It has the smallest molecular weight,

and it is therefore capable of moving faster than the molecules represented by the other answer

choices. In chemistry, effusion is defined as the flow of a gas through a small opening. The rate

of effusion of a substance is inversely proportional to the square root of the density of the

substance. This means that the less dense a substance is, the faster it will effuse. This agrees with

the common observation that thick smoke tends to linger in the same form for a longer period

than thin smoke or steam.

21. Which of the following elements is not involved in many hydrogen bonds?

A. fluorine

B. carbon

C. oxygen

D. nitrogen

Explanation: Carbon is not involved in many hydrogen bonds. A hydrogen bond occurs when

an atom of hydrogen that has a covalent bond with an electronegative atom forms a bond with a

third atom. The original covalent bond involving hydrogen gives away protons, and the third

element receives them. One of the reasons that fluorine, oxygen, and nitrogen are frequently part

of a hydrogen bond is that they have a strong electronegativity and are therefore able to form

more durable bonds. Chlorine is another element frequently involved in hydrogen bonds.

22. What is the mass (in grams) of 0.350 mol copper?

A. 12.5 g

B. 14.6 g

C. 18.5 g

D. 22.2 g

Explanation: The mass of 0.350 mol copper is 22.2 grams. This problem requires the use of the

periodic table. There you will see that the molecular mass of copper is approximately 63.5. Take

this figure and multiply it by the amount of copper given by the question: 0.350 mol. The

resulting figure is 22.225, which, rounded to the nearest tenth, is 22.2 grams. In order to succeed

on the HESI exam, you will need to be able to perform these simple calculations of mass.

23. How many d orbitals are there in a d subshell?

A. 5

B. 7

C. 9

D. 11

Explanation: There are five d orbitals in a d subshell (or sublevel). Each of these orbitals can

hold two electrons, so sublevel d is capable of holding 10 electrons. The s subshell has one

orbital, the p subshell has three orbitals, the d subshell has five orbitals, and the f subshell has

seven orbitals. In chemistry, the electron configuration of an atom is expressed in the following

form, using helium as an example: 1s2. In this notation, the 1 indicates that the electrons are

found in the first energy level of the atom, the s indicates that the electrons are in a spherical

orbit, and the superscript 2 indicates that there are 2 total electrons in the first energy level

subshell.

24. What is the name for the number of protons in an atom?

A. atomic identity

B. atomic mass

C. atomic weight

D. atomic number

Explanation: The number of protons in an atom is the atomic number. Protons are the

fundamental positive unit of an atom. They are located in the nucleus. In a neutral atom (an atom

with neither positive nor negative charge), the number of protons in the nucleus is equal to the

number of electrons orbiting the nucleus. When it needs to be expressed, atomic number is

written as a subscript in front of the element’s symbol, for example in 13Al. Atomic mass,

meanwhile, is the average mass of the various isotopes of a given element. Atomic identity and

atomic weight are not concepts in chemistry.

25. Which of the following elements is an alkali metal?

A. magnesium

B. rubidium

C. hydrogen

D. chlorine

Explanation: Rubidium is an alkali metal. The alkali metals are located in group 1 of the

periodic table. These soft substances melt at a low temperature and are typically white in color.

The alkali metals are lithium, sodium, potassium, rubidium, cesium, and francium. Rubidium,

cesium, and francium are not commonly encountered in the natural world. The alkali metals are

highly reactive, meaning that they easily engage in chemical reactions when combined with other

elements. These metals have a low density and tend to react violently with water.

Chemistry note cards for HESI entrance exam

Question Answer

Matter that has a definite shape and volume solid

Matter that changes in volume with changes in

temperature and pressure gas

A change of matter is when no

change is made to the chemical composition of a

substance.

physical

Simplest of substances and is represented by a

letter or letters element

Law that states matter can neither be created nor

destroyed during a chemical reaction Law of conservation of mass

The breaking of bonds and reforming of new

bonds to create new chemical compounds with

different chemical formulas and different chemical

properties

Chemical reaction

5 main chemical reactions synthesis, decomposition, combustion,

single replacement, double replacement

Chemical reaction in which 2 elements combine to

form a product synthesis

Chemical reaction that is the breaking of a

compound into component parts decomposition

The chemical reaction that is the reaction of a

compound with oxygen combustion

Chemical reaction that consists of an active metal

reaction with an ionic compound creating a new

compound

single replacement

Chemical reaction involving 2 ionic compounds;

the reactant yields "switched partners" double replacement

how elements are arranged on the periodic table by their chemical properties

Number that represents the # of protons an

element has atomic number

average of the masses of each of its isotopes as

they occur in nature atomic mass

Mass number - atomic number = # of neutrons in an element

Columns of the periodic table = groups

Rows of the periodic table = periods

Group IA = charge +1

Group IIA = charge +2

Group IIIA = charge +3

Group VA = charge -3

Group VIA = charge -2

Group VIIA = charge -1

Charge of noble gases 0

Positively charged ions protons

Negatively charged ions electrons

Neutral ions neutrons

# of proteins in an element = atomic number

proteins + neutrons = mass number

In reactions, atoms try to reach stable

electron configurations. chemical

reactions take place in the nucleus,

to obtain stable nuclear configurations. nuclear

Word used to describe the emission of particles

from an unstable nucleus. radioactivity

The particles that are emitted during radioactivity radiation

3 types of radiation alpha, beta, gamma

Radiation that is the emission of helium ions alpha

Alpha radiation particles have a charge of +2

How can penetration from alpha particles be

stopped? piece of paper

Radiation that is a product of the decomposition of

a neutron. It is composed of high-speed, highenergy electrons.

beta radiation

How can beta radiation particles be stopped? aluminum foil

radiation is high-energy electromagnetic

radiation that lacks charge and mass.

gamma

What radiation can be stopped by several feet of

concrete or several inches of lead? gamma radiation

2 types of chemical bonding ionic & covalent

What bond is an electrostatic attraction between 2

oppositely charged ions? (between metals &

nonmetals)

ionic

A single bond is formed when 2 atoms

share a pair of electrons. covalent

A bond is formed when 2 electron pairs

are shared. double covalent

A bond is formed when 3 electron pairs

are shared. triple covalent

What is the strongest type of chemical bond?

What is it formed by? covalent bond; non-metals

In a covalent bond compound, if the electrons are

shared equally, then the bond is .

non-polar

If electrons are not shared equally in a covalent

bond, the bond is .

polar

is based on the difference in

electronegativity values for the elements involved polarity

Hydrogen bonding, dipole interactions and

dispersion forces. intermolecular forces

Bond that is the attraction for a hydrogen atom by

a highly electronegative element. hydrogen bond

Elements fluorine, chlorine, oxygen and nitrogen

are generally involved in a bond. hydrogen

Bond that is the strongest of the intermolecular

forces hydrogen

The attractions of one dipole for another dipole interactions

A is created when an electron pair in a

covalent bond is shared unequally dipole

A dipole attraction is a _ intermolecular

force. weak

The weakest of all intermolecular forces. dispersion forces

Dispersion forces are typically found in

covalent compounds. Non-polar

6.02 x 10^23 is a mole

The mass of one mole of a substance atomic mass

The part of chemistry that deals with the quantities

and numeric relationships between compounds in

a chemical reaction.

stoichiometry

To balance an equation, are placed in front

of each component. coefficient

4 ways to increase the reaction rate

increase temperature, increase surface

area, increase concentrations and reactants

and add a catalyst

Increasing the causes the particles to

have greater kinetic energy, allowing them to

move faster and have a greater chance

temperature

Accelerates a reaction by reducing the activation

energy, or the amount of energy needed for a

reaction to occur.

catalyst

reaction involve the transfer of

electrons from one element to another redox

The loss of electrons oxidation

The gain of electrons reduction

Sum of oxidation #'s = The charge on polyatomic ions

Compounds acting as hydrogen-ion donors acids

Compounds acting a hydrogen-ion acceptor bases

pH value less that 7.0; taste sour/tart; produce

h30+ (most of their formulas begin with H) acids

Produce OH-; taste is bitter, feels slippery;

conduct electricity; formulas contain OH-, pH

value is greater than 7.0

bases

What characterizes a chemical reaction as

combustion? adding O2

What is the change of potassium in KCl? +1 because K is found in group IA

How many electrons does an oxygen ion have

10 (it has an atomic # of 8 and is in group

VIA, which has a -2 charge, which means

it has 2 more electrons than he 8 protons).

How many neutrons does an atom of carbon -14

contain?

8 (take the mass #-atomic # = neutrons)

14-6=8

What is the strongest type of chemical bond? covalent bond

What is the mass of one mole of CO2? 44g/mol (C=12.011 + (15.999 x 2) =

answer)

How many moles are present in 2 moles of O2? 1.204 x 10^24 (1 mole - 6.02 x 10^23, 2

mole would be double that)

What would be the oxidation state of the sulfur

atom in sulfuric acid, H2SO4? +6

CHEMISTRY V1/V2 (140 Questions and Answers)From test

1. If Hydrogen is in a compound, what would its oxidation number be?

+1

2. What is the oxidation number of any simple ion?

The same as the charge of the ion

3. How many kilograms are in a pound?

0.453592 kg

4. What is the temperature for freezing point of water in Celsius?

0 degrees Celsius (32°F for Fahrenheit)

5. What is the conversion of Celsius to Fahrenheit?

5F=9C+160 (remember 5F because you have 5 fingers on a hand & 9C because cats

have 9 lives)

6. What is the oxidation number of an element atom?

0

7. What is the freezing point of sea water in Fahrenheit?

Below 0C (pick and answer choice around -2C, actual temp depends on how much salt

is in the water)

8. How many amino acids are in a dipeptide?

2

9. If Oxygen is in a compound, what would its oxidation number be?

-2

10. Which of the following pH values would lemon juice likely have?

2 because the lower the pH value, the more acidic

11. What is a pentose?

A 5 carbon sugar (Pent = 5) (ose = sugar)

12. What is the oxidation state of the Sulfur atom in Sulfuric Acid H2SO4?

6 (each H is +1, each O is -2. All charges have to add to 0. 2+S-8=0, so S=6)

13. How many neutrons does carbon 14 have?

8 ( mass# - atomics # = neutrons) 14 - 6 = 8

14. How many protons does Potassium have?

19 (same as the atomic number)

15. How many amino acids are essential for human life?

20 amino acids

16. Normal body temperature in °C?

37°C

17. Normal body temperature in °F?

98.6°F

18. Boiling point of water in °C?

100°C

19. Boiling point of water in °F?

212°F

20. 0°K is equal to °C?

-273°C

21. The term Amphoteric means?

A substance that can act as both a base & acid

22. What is Kelvin based around?

Absolute zero

23. A compound that is a Hydrogen or proton donor, corrosive to metals, causes blue

litmus paper to become red and becomes less acidic when mixed with a base is?

Acid

24. Mixture of 2 or more metals are?

Alloys

25. Acids:

• pH less than 7.0

• sour/tart

• Formulas begin with H (Hydrogen)

• Proton Donor

26. 3 types of radiation in nuclear chemistry?

Alpha, Beta & Gamma

27. Alpha radiation:

• * Emission of Helium (He) ions in the nuclei

• * Contains 2 protons & 2 neutrons.

• * +2 Charge

• * Largest radiation particle.

• * Can be stopped by piece of paper

28. Type of Alloy in which another metal is dissolved in Mercury (Hg)?

Amalgam

29. Proteins are made up of?

Amino Acids

30. Glycogen is what kind of starch?

Animal Starch

31. When an atom GAINS ONE or more electrons?

Anions (negative ion)

32. Basic building block of a molecule?

Atom

33. Atomic mass?

Average mass of an elements isotope

34. Atomic #:

# of protons in nucleus of an atom

35. Base?

• A Hydrogen or proton ACCEPTOR & has hydroxide group in the makeup of the

molecule

• Produce -OH

• Bitter, slippery, conduct electricity, formulas contain -OH

• pH value greater than 7.0

• Proton acceptor

36. Key note:

Acids are Proton donors and Bases are proton acceptors

37. Beta radiation:

• Decomposition product of a proton or neutron

• High speed/energy Electrons

• EITHER - charged electrons or + charged positrons

• Can be stopped by aluminum foil

38. What is Biochemistry?

Study of substances & processes occurring in living things

39. Fahrenheit is based off of?

Body temperature

40. How does ↑ Surface area speed up chemical reactions?

By ↑ areas of contact where chemical reactions can occur

41. How do catalyst accelerate a chemical reaction?

By reducing the amount of energy needed for a reaction to occur

A catalyst is a substance that accelerates a reaction by which of the following? -Finding

an alternative pathway for a reaction that requires less energy.

42. What does COOH symbolize?

A Carboxyl group

43. Which of the following is not a solution type?

Catalyst

44. Define Catalyst.

Substance that speeds up a chemical reaction.

45. What is an atom called when it LOSES 1 or more electrons?

Cations (positive ions)

46. What is chemical bonding?

The joining of atoms to form new substances. 2 types: ionic & covalent bonding

47. What is an Ionic bond?

• Electrical attraction between 2 oppositely charged atoms called ions

• (between metals & nonmetals)

48. Ionic bonding?

Chemical bond that’s formed when an atom transfers an electron to another atom.

(steals)

49. Single Covalent bond?

• Chemical bond that shares 1 electron pair

• Formed by non-metals

• Sharing is caring! Caring is covalent!

50. What are chemical reactions?

Making & breaking of chemical bonds, leading to changes in composition of matter

51. Double Covalent bond?

When 2 electron pairs are shared

52. Triple Covalent bond?

When 3 electron pairs are shared

53. The following is an example of?

Combustion reaction (in combustion, O2 is always a reactant, CO2 and H2O are always

products the second reactant is the compound being combusted)

2C2H6 (g) + 7O2 (g) 4CO2(g) + 6H2O

54. What is a combustion reaction?

A chemical reaction that occurs when a substance reacts with Oxygen, releasing energy

in the form of heat & light (also releases carbon dioxide & water)

55. What is a compound?

• Combination of 2 or more elements or atoms.

• Made up of atoms of 2 or more different elements joined by chemical bonds

56. Different types of solutions?

Compounds, Alloys, Amalgams, Emulsions

57. Strongest type of chemical bond?

Covalent

58. What is a decomposition reaction?

A SINGLE compound breaks down to form 2 or more simpler substances

59. What is Deoxyribose?

A sugar used in the formation of DNA

60. Attractions between opposite charges of polar moles?

Dipole-dipole forces

61. What is a Disaccharide?

A double sugar molecule made of 2 monosaccharides bonded together through

dehydration synthesis.

62. When 2 monosaccharides are joined together this makes?

Disaccharide

63. Type of chemical bond that share 2 electron pairs?

Double covalent bond

64. Example of double replacement?

AB + CD = AD + CB (swapping dance partners)

65. Example of Single replacement?

A + BC  B + AC (one dancer cutting in on two partners)

66. Group of electrons revolving around the nucleus of an atom, or known as a cloudlike

group of electrons?

Electron clouds

67. Mixtures of matter that readily separate such as water and oil?

Emulsion

68. 3 common temperature systems?

Fahrenheit, Celsius, Kelvin

69. Celsius is based around?

Freezing & boiling point of water

70. What is oxidation?

Loss of electrons (OIL: oxidation is losing)

71. What is reduction?

GAIN of electrons (RIG: reduction is gaining)

72. Gamma radiation:

• Similar to xrays

• Can be stopped by several feet of concrete or several inches of Lead

• High energy electromagnetic radiation lacking charge and mass

73. Unit measure of weight?

Gram

74. Basic units of METRIC system?

Gram, Liter, Meter

75. What are Hydrogen bonds?

Weak attraction between a hydrogen atom in one molecule & another atom in a

different molecule.

76. Examples of intermolecular forces?

Hydrogen bonds, dipole-dipole, dispersion forces (attractions between two different

molecules. Intramolecular bonds are ionic & covalent bonds within a single molecule)

77. 4 basic ways to speed up a reaction?

↑ temperature, ↑ Surface area, ↑ catalyst & ↑concentration

78. What are intermolecular forces?

Forces of attractions between molecules

79. Where are nucleic acids, DNA & RNA found?

Cell nucleus

80. Atoms of the same element but have different numbers of neutrons?

Isotope

81. Gluconeogenesis is a process that produces?

Glucose from proteins and fats rather than carbohydrates

82. A way to express concentration of atoms?

Molarity

83. Part of the nucleus of an atom that has no charge?

Neutron

84. What is the Molarity Formula?

???????????????????? ???????? ????????????????????????

???????????????????????? ???????? ????????????????????????????????

= ????????????????????????????????

85. Single sugar molecules?

Monosaccharides

86. How does ↑ concentration cause reaction acceleration?

More potential for contact (chemical reaction)

87. Which is an example of a ionic bond?

NaCl (Sodium Chloride) because it contains a metal and a non-metal (metal is always

first)

88. In a covalent bond compound, if the electrons are shared equally, then the bond is?

Non-polar (water hating, equal)

89. The study of changes that occur in atomic nuclei?

Nuclear Chemistry

90. Polar Covalent bond?

Unequal sharing of electrons (water loving)

91. When 3-6 monosaccharides join together this is called?

Oligosaccharide (7 or more: polysaccharide. Sometimes 3 or more is called a

polysaccharide)

92. Emission of particles or energy from an unstable nucleus?

Radioactivity

93. Particles that are emitted during radioactivity?

Radiation

94. Reactant is?

A chemicalsubstance that is present atthe start of a chemicalreaction.

Reactant  Product

95. A substance that is dissolved in a solution?

Solute (the liquid it is dissolved in is the solvent. In salt water, salt is the solute &

water is the solvent)

96. A homogenous mixture of 2 or more substances?

Solution

97. Liquid substance capable of dissolving other substances?

Solvent

98. Define stoichiometry.

Calculation of quantities in chemical reactions

99. Combining parts into a whole is? Or synthesis is?

• Synthesis

• Chemical reaction in which 2 elements or simpler compounds combine to form a

product

100. How many electrons does an Oxygen ion have?

10 (Atomic # of 8 & is in group VIA which has a -2 charge, which means it has 2 more

electrons than the 8 protons)

101. What is the charge of Potassium (K) in KCl?

+1 because K is found in group IA

102. What is the mass of 1 mole of CO2?

44g/mol (C =12.011 + (15.999 x 2) = answer. You will be given the masses of the

individual elements)

103. How many moles of atoms are present in 2 moles of O2?

4 (2 atoms in each molecule x 2 moles = 4 moles)

104. What characterizes a chemical reaction as combustion? The chemical reaction that is

the reaction of a compound with Oxygen?

• O2 is a reactant, CO2 and H2O areproducts

• Combustion

105. Sum of oxidation # =?

Charge on polyatomic ion

106. Increasing the causes the particles to have greater kinetic energy, allowing them to

move faster and have a greater chance of reacting.

Temperature

107. To balance an equation, what is placed in front of each component?

Coefficient

108. Dispersions forces are found in which covalent bond?

All (polar and non-polar)

109. The weakest of all intermolecular forces?

Dispersion forces

110. A Dipole attraction is a __ intermolecular force?

Weak

111. What is created when an electron pair in a covalent bond is shared unequally?

Dipole

112. The attractions of one dipole to another is?

Dipole interactions

113. Strongest bond of intermolecular forces?

Hydrogen bond (but weaker than ionic and covalent, which are intramolecular bonds)

114. Elements Flourine (F), Chlorine (Cl ), Oxygen (O) and Nitrogen (N) are involved in

which bond?

Hydrogen bond

115. Polarity is?

Based on the difference in electronegativity values for the elements involved

116. What reactions take place in the nucleus to obtain stable nuclear configurations?

Nuclear reactions

117. Mass # - Atomic # = # Neutrons in an element

118. Protons + Neutrons = Mass #

119. # of Protons in an element = Atomic #

120. Neutral subatomic particles = Neutrons

121. – charge subatomic particles = electrons

122. + charge subatomic particles = Protons

123. Charge of noble gases?

0

124. Group IA = +1 Charge

125. Group IIA = +2 Charge

126. Group IIIA = +3 Charge

127. Group VA = -3 Charge

128. Group VIA = -2 Charge

129. Group VIIA = -1 Charge

130. Rows on periodic table:

Period (Horizontal Left/right) (remember: “R” and “P” look very similar)

131. Columns of periodic table:

Group (Vertical up/down) (remember: “C” and “G” look very similar)

132. How elements are arranged on the periodic table?

By their chemical properties

133. Matter that has definite shape & volume?

Solid

134. Matter that changes in volume with changes in temperature & pressure?

Gas

135. Which change of matter is when no change is made to the chemical composition of a

substance?

Physical (if the chemical composition changes, it’s a chemical change. Boiling water is

physical because it’s H2O before and after. Changing H2O to H2 and O2 is a chemical

change)

136. Simplest substance and is represented by a letter or letters?

Element

137. Law that states matter can neither be created nor destroyed during a chemical reaction

(but it can change forms)?

Law of conservation of mass

138. Law that states energy can neither be created nor destroyed (but it can change forms)?

Law of conservation of energy

1-H 2-HE

3

- LI

4

- BE 5 B

6

-

C N 7 0 8 F9 NE 10

11

- NA 12

- Mg 13

- AL 14

-SI 15

-

P 16

-

S 17

-Cl 18

-Ar

K

- 19 CA

- 20