CST Practice Test. Multiple Choice Questions

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CST Practice Test

Young

NAME

CST Practice Test

Multiple Choice Questions

1) At 1 atm and 298 K, which of the Kavalues listed below

represents the strongest acid?

(a) 1.1 × 10−7 (c) 5.6 × 10−11 (b) 1.8 × 10−5 (d) 4.6 × 10−4

2) Given the system at equilibrium:

PbCO3(s) Pb2+(aq) + CO32−(aq)

How will the addition of Na2CO3(aq) affect [Pb2+](aq)

and the mass of PbCO3(s)?

(a) [Pb2+](aq) will decrease and the mass of PbCO3(s)

will decrease.

(b) [Pb2+](aq) will decrease and the mass of PbCO3(s)

will increase.

(c) [Pb2+](aq) will increase and the mass of PbCO3(s)

will decrease.

(d) [Pb2+](aq) will increase and the mass of PbCO3(s)

will increase.

3) When a catalyst is added to a system at equilibrium, a decrease occurs in

(a) the heat of the reaction (b) activation energy

(c) potential energy of the reactants (d) potential energy of the products

4) Given the reaction at equilibrium: X + Y 2Z + heat

The concentration of the product could be increased by (a) adding a catalyst

(b) adding more heat to the system (c) increasing the concentration of Y (d) decreasing the concentration of X

5) Which electron-dot symbol represents an atom of chlo-rine in the ground state?

(a) (c)

(b) (d)

6) Which statement describes the elements in Period 3? (a) Each successive element has a greater atomic

ra-dius.

(b) Each successive element has a lower electronegativ-ity.

(c) All elements have similar chemical properties. (d) All elements have valence electrons in the same

principal energy level.

7) What volume will a 300.-milliliter sample of a gas at STP occupy when the pressure is doubled at constant temperature?

(a) 150. mL (c) 300. mL

(b) 450. mL (d) 600. mL

8) Which type of bond is formed when an atom of potas-sium transfers an electron to a bromine atom?

(a) metallic (c) nonpolar covalent

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9) C3H8 + 5O2→ 3CO2 + 4H2O

Which of these could be added to the above re-action to increase the rate of rere-action over time?

(a) C3H8 and O2

(b) C3H8and CO2

(c) O2and CO2

(d) O2and H2O

10) The heat energy required to change a unit mass of a solid into a liquid at constant temperature is called

(a) heat of vaporization (c) heat of solution (b) heat of formation (d) heat of fusion

11) Given the reaction at equilibrium:

2A(g) + 3B(g) A2B3(g) + heat

Which change will not affect the equilibrium concen-trations of A(g), B(g), and A2B3(g)?

(a) adding more A(g) (b) adding a catalyst

(c) increasing the temperature (d) increasing the pressure

12) What occurs when a substance melts?

(a) It changes from solid to liquid, and heat is ab-sorbed.

(b) It changes from solid to liquid, and heat is re-leased.

(c) It changes from liquid to solid, and heat is ab-sorbed.

(d) It changes from liquid to solid, and heat is re-leased.

13) Which phase change is exothermic?

(a) solid to liquid (c) liquid to solid (b) solid to gas (d) liquid to gas

14) A student observed that when sodium hydroxide was dissolved in water, the temperature of the water in-creased. The student should conclude that the dis-solving of sodium hydroxide

(a) is endothermic (b) is exothermic

(c) produces an acid solution (d) produces a salt solution

15) Given the nuclear equation: 14 7 N + X → 16 8 O + 2 1 H What is particle X?

(a) an alpha particle (c) a deuteron (b) a beta particle (d) a triton

16) Given the reaction:

N2(g) + 3H2(g) 2NH3(g) + energy

If the temperature is increased and the pressure is kept constant, the new equilibrium concentration will be

(a) less for NH3(g) (c) less for N2(g) (b) the same for NH3(g) (d) the same for N2(g)

17) In a mixture of water, sugar, and salt, which ingredi-ent(s), if any, are solvents?

(a) Water only

(b) Water and sugar only (c) Sugar and salt only (d) Water, sugar, and salt

18) Which property do most acids share? (a) Bitter taste

(b) Sour taste (c) Slippery feel (d) Faint color

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2N2(g) + O2(g) 2N2O(g)

Which statement is true when this closed system reaches equilibrium?

(a) All of the N2(g) has been consumed.

(b) All of the O2(g) has been consumed.

(c) Pressure changes no longer occur. (d) The forward reaction no longer occurs.

20) Which type of bond exists between an atom of carbon and an atom of fluorine?

(a) ionic (c) polar covalent

(b) metallic (d) nonpolar covalent

21) Which of these is the best conductor of electricity? (a) Distilled water

(b) Salt water (c) Carbonated water (d) Sugar water

22) The ability of H2SO4(aq) to change blue litmus red is

mainly due to the presence of

(a) SO2 molecules (c) H3O+(aq) ions

(b) H2O molecules (d) SO42−(aq) ions

23) If equal volumes of 0.1 M NaOH and 0.1 M HCl are mixed, the resulting solution will contain a salt and

(a) HCl (c) H2O

(b) NaOH (d) NaCl

24) Carbon dioxide gas is most soluble in water under con-ditions of

(a) high pressure and low temperature (b) high pressure and high temperature (c) low pressure and low temperature (d) low pressure and high temperature

25) In a reversible chemical reaction, which factors must be equal when the reaction is at equilibrium?

(a) rate at which reactants are formed and rate at which products are formed

(b) concentration of reactants and concentration of products

(c) potential energy of reactants and potential energy of products

(d) activation energy of reactants and activation en-ergy of products

26) In a reversible reaction, chemical equilibrium is at-tained when the

(a) rate of the forward reaction is greater than the rate of the reverse reaction

(b) rate of the reverse reaction is greater than the rate of the forward reaction

(c) concentration of the reactants reaches zero (d) concentration of the products remains constant

27) What are the characteristics of a neutron? (a) It has no charge and no mass.

(b) It has no charge and a mass of 1 amu. (c) It has a charge of +1 and no mass.

(d) It has a charge of +1 and a mass of 1 amu.

28) Given the solution at equilibrium:

PbI2(s) Pb2+(aq) + 2I−(aq)

The addition of which nitrate salt will cause a decrease in the concentration of I−(aq) ?

(a) Pb(NO3)2 (c) LiNO3

(b) Ca(NO3)2 (d) KNO3

29) Which properties are most common in nonmetals? (a) low ionization energy and low electronegativity (b) low ionization energy and high electronegativity (c) high ionization energy and low electronegativity (d) high ionization energy and high electronegativity

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30) Which ion has the largest radius?

(a) Na+ _{(c) K}+

(b) Mg2+ _{(d) Ca}2+

31) The forces between atoms that create chemical bonds are the result of interactions between

(a) nuclei (b) electrons

(c) protons and electrons (d) protons and nuclei

32) The graph below represents the uniform cooling of a substance, starting with the substance as a gas above its boiling point.

During which interval is the substance completely in the liquid phase?

(a) AB (c) CD

(b) BC (d) DE

33) The energy absorbed when ammonium chloride dis-solves in water can be measured in

(a) degrees (c) moles per liter (b) kilocalories (d) liters per mole

34) What happens when NaCl(s) is dissolved in water? (a) Cl−ions are attracted to the oxygen atoms of

wa-ter molecules.

(b) Na+ ions are attracted to the oxygen atoms of water molecules.

(c) Cl− _{ions are repelled by the hydrogen atoms of}

water molecules.

(d) Na+_{ions are repelled by the oxygen atoms of}

wa-ter molecules.

35) Which pair of atoms is held together by a covalent bond?

(a) HCl (c) NaCl

(b) LiCl (d) KCl

36) A condensation polymerization reaction is best de-scribed as the

(a) joining of monomers by the removal of oxygen (b) joining of monomers by the removal of water (c) oxidation of a hydrocarbon by oxygen (d) oxidation of a hydrocarbon by water

37) As the number of neutrons in the nucleus of a given atom of an element increases, the atomic number of that element

(a) decreases (c) remains the same (b) increases

38) Experiments performed to reveal the structure of atoms led scientists to conclude that an atom’s

(a) positive charge is evenly distributed throughout its volume

(b) negative charge is mainly concentrated in its nu-cleus

(c) mass is evenly distributed throughout its volume (d) volume is mainly unoccupied

39) The nucleus of which atom contains 48 neutrons? (a) 32 16 S (c) 85 37 Rb (b) 48 22 Ti (d) 112 48 Cd

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40) When an atom loses an electron, the atom becomes an ion that is

(a) positively charged and gains a small amount of mass

(b) positively charged and loses a small amount of mass

(c) negatively charged and gains a small amount of mass

(d) negatively charged and loses a small amount of mass

41) Which shows the correct Lewis structure for H2O?

(a)

_H

_O

_H

(b)

H

O

H

(c)

_{H O H}

(d)

_H

_O

_H

42) The atomic mass unit is defined as exactly ₁₂1 the mass of an atom of (a) 12 6 C (c) 24 12 Mg (b) 14 6 C (d) 26 12 Mg

43) Which type of radiation continues in a straight line when passed through an electric field?

(a) alpha (c) gamma

(b) beta (d) proton

44) Which atom in the ground state has five electrons in its outer level and ten electrons in its kernel?

(a) C (c) Si

(b) Cl (d) P

45) Which list of substances is in order of increasing in-termolecular forces?

(a) Ice, soda, honey, helium (b) Soda, ice, honey, helium (c) Helium, soda, honey, ice (d) Helium, soda, ice, honey

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46) The forward reaction is best described as an

(a) exothermic reaction in which energy is released (b) exothermic reaction in which energy is absorbed (c) endothermic reaction in which energy is released (d) endothermic reaction in which energy is absorbed

47) As HCl(g) is added to water, the pH of the water solution

(a) decreases (c) remains the same (b) increases

48) Which list is in order of increasing penetrating strength?

(a) Alpha, gamma, beta (b) Alpha, beta, gamma (c) Gamma, alpha, beta (d) Gamma, beta, alpha

49) An increase in the temperature of a system at equilib-rium favors the

(a) endothermic reaction and decreases its rate (b) endothermic reaction and increases its rate (c) exothermic reaction and decreases its rate (d) exothermic reaction and increases its rate

50) How are protons held together in the nucleus of an atom?

(a) Nuclear forces

(b) Electromagnetic attraction (c) Electromagnetic repulsion (d) Rotational inertia

51) What is the concentration of a solution of 10. moles of copper (II) nitrate in 5.0 liters of solution?

(a) 0.50 M (c) 5.0M

(b) 2.0 M (d) 10. M

52) Which of these has base units made up of amino acids? (a) Protein

(b) Phospholipids (c) Sucrose (d) DNA

53) Which of these combine together to form proteins? (a) Amino acids

(b) Lipids (c) Sugars (d) Nucleic acids

54) Which element in Group 1 has the greatest tendency to lose an electron?

(a) cesium (c) potassium

(b) rubidium (d) sodium

55) The diagram below represents radiation passing through an electric field.

The arrow labeled A most likely represents (a) a positron (c) alpha radiation (b) an electron (d) gamma radiation

56) What is the total number of valence electrons in an atom of xenon?

(a) 0 (c) 8

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57) The bond between hydrogen and oxygen in a water molecule is classified as

(a) ionic and nonpolar (b) ionic and polar (c) covalent and nonpolar (d) covalent and polar

58) When ionic bonds are formed, metallic atoms tend to (a) lose electrons and become negative ions (b) lose electrons and become positive ions (c) gain electrons and become negative ions (d) gain electrons and become positive ions

59) Which phase change is exothermic? (a) H2O(s) → H2O(`)

(b) H2O(`) → H2O(s)

(c) H2O(s) → H2O(g)

(d) H2O(`) → H2O(g)

A2(g) + B2(g) 2AB(g) + heat

An increase in the concentration of A2(g) will

(a) decrease the production of AB(g)

(b) decrease the frequency of collisions between A2(g)

and B2(g)

(c) increase the production of B2(g)

(d) increase the frequency of collisions between A2(g)

and B2(g)

61) Which subatomic particle is found in the nucleus of all isotopes of hydrogen?

(a) proton (c) electron

(b) neutron (d) positron 62) In the equation 234 90 Th → 234 91 Pa + X the symbol X represents (a) 0 +1 e (c) 1 0 n (b) 0 −1 e (d) 1 1 H

63) A gas sample has a volume of 25.0 milliliters at a pres-sure of 1.00 atmosphere. If the volume increases to 50.0 milliliters and the temperature remains constant, the new pressure will be

(a) 1.00 atm (c) 0.250 atm

(b) 2.00 atm (d) 0.500 atm

64) Which noble gas has the highest first ionization en-ergy?

(a) radon (c) neon

(b) krypton (d) helium

65) Which statement explains why fusion reactions are dif-ficult to initiate?

(a) Positive nuclei attract each other. (b) Positive nuclei repel each other.

(c) Neutrons prevent nuclei from getting close enough to fuse.

(d) Electrons prevent nuclei from getting close enough to fuse.

Cl(g) + Cl(g) → Cl2(g) + energy

Which statement best describes the reaction? (a) A bond is formed and energy is absorbed. (b) A bond is formed and energy is released. (c) A bond is broken and energy is absorbed. (d) A bond is broken and energy is released.

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67) The reaction during which monomers are combined and water is released is called

(a) saponification (b) neutralization

(c) addition polymerization (d) condensation polymerization

68) A catalyst will affect the rate of the forward reaction by changing the

(a) activation energy (b) heat of reaction (c) heat of formation

(d) potential energy of the products

69) What is the correct formula for magnesium fluoride? (a) MgF

(b) Mg2F

(c) Mg2F2

(d) MgF2

70) If M represents an alkali metal, what is the formula for the compound formed by M and oxygen?

(a) MO2 (c) M2O3

(b) M2O (d) M3O2

71) Which formula correctly represents antimony (V) ox-ide?

(a) SbO5 (c) Sb2O5

(b) Sb5O (d) Sb5O2

72) Which acid-base pair will always undergo a reaction that produces a neutral solution?

(a) a weak acid and a weak base (b) a weak acid and a strong base (c) a strong acid and a weak base (d) a strong acid and a strong base

73) Hotter temperatures generally make less soluble in water.

(a) gases (b) solids (c) liquids (d) salts

74) Why does a spoonful of loose salt crystals dissolve faster in water than does a block of the same amount of salt?

(a) The loose salt crystals require less energy to dis-solve than the block of salt.

(b) The loose salt crystals have more surface area ex-posed to the water than the block of salt. (c) The loose salt crystals are less soluble than the

block of salt.

(d) The loose salt crystals have fewer chemical bonds to break than the block of salt.

75) Which two elements have chemical properties that are most similar?

(a) Cl and Ar (c) K and Ca

(b) Li and Na (d) C and N

76)

Carbonated beverages are bottled and canned under pressure, because pressure greatly−

(a) decreases the solubility of solids in liquids. (b) increases the solubility of solids in liquids. (c) decreases the solubility of gases in liquids. (d) increases the solubility of gases in liquids.

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77) How does the temperature of water influence the sol-ubility of different substances?

(a) Hotter water generally makes solids more soluble. (b) Colder water generally makes liquids more soluble. (c) Hotter water generally makes gases more soluble. (d) Water temperature does not affect the solubility

of substances.

78) When HCl is dissolved in water, the only positive ion present in the solution is the

(a) hydrogen ion (c) hydride ion (b) hydroxide ion (d) chloride ion

79) Given the solution at equilibrium:

CaSO4(s) Ca2+(aq) + SO42−(aq)

When Na2SO4 is added to the system, how will the

equilibrium shift?

(a) The amount of CaSO4(s) will decrease, and the

concentration of Ca2+ _{(aq) will decrease.}

(b) The amount of CaSO4(s) will decrease, and the

concentration of Ca2+ _{(aq) will increase.}

(c) The amount of CaSO4(s) will increase, and the

concentration of Ca2+(aq) will decrease.

(d) The amount of CaSO4(s) will increase, and the

concentration of Ca2+(aq) will increase.

80) Given the nuclear reaction: 9 4 Be + X → 12 6 C + 1 0 n What is the identity of particle X?

(a) alpha particle (c) proton (b) beta particle (d) neutron

81) In which list can all particles be accelerated by an electric field?

(a) alpha particles, beta particles, and neutrons (b) alpha particles, beta particles, and protons (c) alpha particles, protons, and neutrons (d) beta particles, protons, and neutrons

82) Adding a catalyst to a chemical reaction changes the rate of reaction by causing

(a) a decrease in the activation energy (b) an increase in the activation energy (c) a decrease in the heat of reaction (d) an increase in the heat of reaction

83) In which pair of elements do the nuclei of the atoms contain the same number of neutrons’ ?

(a) 7 3 Li and 9 4 Be (c) 23 11 Na and 24 12 Mg (b) 14 7 N and 16 8 O (d) 32 16 S and 35 17 Cl

84) The properties of carbon are expected to be most sim-ilar to those of

(a) boron (c) silicon

(b) aluminum (d) phosphorus

85) Which type of radiation is most similar to high-energy x rays?

(a) alpha (c) neutron

(b) beta (d) gamma

86) When an acid is dissolved in water, it will− (a) release H+ _{ions into the water.}

(b) release H− ions into the water. (c) release OH− ions into the water. (d) not release ions into the water.

87) Which atom will form an ionic bond with a Br atom?

(a) N (c) O

(b) Li (d) C

88) What is the pH of a solution that results from the com-plete neutralization of an HCl solution with a KOH solution?

(a) 1 (c) 10

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89) Which atoms are isotopes of the same element? (a) 24 12 X and 25 12 X (c) 31 15 X and 32 16 X (b) 20 10 X and 20 11 X (d) 31 19 X and 31 19 X

90) Which subatomic particles have a mass of approxi-mately 1 atomic mass unit each?

(a) proton and electron (b) proton and neutron (c) neutron and positron (d) electron and positron

91) Given the reaction at equilibrium: A(g) + B(g) C(g) + D(g) The addition of a catalyst will

(a) shift the equilibrium to the right (b) shift the equilibrium to the left

(c) increase the rate of forward and reverse reactions equally

(d) have no effect on the forward or reverse reactions

BaCrO4(s) Ba2+(aq) + CrO2−4 (aq)

Which substance, when added to the mixture, will cause an increase in the amount of BaCrO4(s)?

(a) K2CO3 (c) BaCl2

(b) CaCO3 (d) CaCl2

2SO2(g) + O2(g) 2SO3(g)

The value of the equilibrium constant (Keq) will be

changed by increasing the (a) pressure

(b) temperature

(c) concentration of SO2(g)

(d) concentration of SO3(g)

94) Which change of phase is exothermic?

(a) solid to liquid (c) solid to gas (b) gas to liquid (d) liquid to gas

95) Proteins are produced through the process of (a) addition (c) polymerization (b) substitution (d) combustion

96) The mass of a calcium atom is due primarily to the mass of its

(a) protons, only (b) neutrons, only (c) protons and neutrons (d) protons and electrons

97) Which statement about the mass of an electron is cor-rect?

(a) The mass of an electron is equal to the mass of a proton.

(b) The mass of an electron is less than the mass of a proton.

(c) The mass of an electron is equal to the mass of a neutron.

(d) The mass of an electron is greater than the mass of a neutron.

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98) A potential energy diagram of a chemical reaction is shown below.

What is the difference between the potential energy of the reactants and the potential energy of the prod-ucts?

(a) 20 kcal (c) 60 kcal

(b) 40 kcal (d) 80 kcal

99) What is the atomic number of an element that has six protons and eight neutrons?

(a) 6 (c) 8

(b) 2 (d) 14

100) Given the reaction: 226

88 Ra → 222

86 Rn + X Which type of emanation is represented by X?

(a) alpha particle (c) proton (b) beta particle (d) positron

101) Given the system at equilibrium:

H2(g) + F2(g) 2HF(g) + heat

Which change will not shift the point of equilibrium? (a) changing the pressure

(b) changing the temperature

(c) changing the concentration of H2(g)

(d) changing the concentration of HF(g)

102) What is the molarity of a solution that contains 40. grams of NaOH in 0.50 liter of solution?

(a) 1.0 M (c) 0.50 M

(b) 2.0 M (d) 0.25 M

103) Which graph best shows the relationship between Kelvin temperature and average kinetic energy?

(a) (c)

(b) (d)

104) When alpha particles are used to bombard gold foil, most of the alpha particles pass through undeflected. This result indicates that most of the volume of a gold atom consists of

(a) neutrons (c) deuterons (b) protons (d) unoccupied space

105) Atoms of metals tend to

(a) lose electrons and form negative ions (b) lose electrons and form positive ions (c) gain electrons and form negative ions (d) gain electrons and form positive ions

106) Which of the following 0.1 M solutions has the lowest pH’ ?

(a) 0.1 M NaOH (c) 0.1 M NaCl (b) 0.1 M CH3OH (d) 0.1 M HCl

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107) Which of the following elements has the strongest attraction for electrons?

(a) boron (c) oxygen

(b) aluminum (d) sulfur

108) Which particles may be gained, lost, or shared by an atom when it forms a chemical bond?

(a) protons (c) neutrons

(b) electrons (d) nucleons

109) The potential energy diagram of a chemical reaction is shown below.

Which arrow represents the part of the reaction most likely to be affected by the addition of a catalyst?

(a) A (c) C

(b) B (d) D

N2(g) + 3H2(g) 2NH3(g) + 22 kcal

Which stress would cause the equilibrium to shift to the left?

(a) increasing the temperature (b) increasing the pressure (c) adding N2(g) to the system

(d) adding H2(g) to the system

111) What is the total number of valence electrons in an atom of boron in the ground state?

(a) 1 (c) 3

(b) 7 (d) 5

112) What is the total number of protons and neutrons in an atom of 86

37 Rb?

(a) 37 (c) 86

(b) 49 (d) 123

113) Which type of radiation has zero mass and zero charge?

(a) alpha (c) neutron

(b) beta (d) gamma

114) The elements known as the alkaline earth metals are found in Group

(a) 1 (c) 16

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CST Practice Test

Young

Answer Key

Multiple Choice Questions

1) d 2) b 3) b 4) c 5) d 6) d 7) a 8) b 9) a 10) d 11) b 12) a 13) c 14) b 15) a 16) a 17) a 18) b 19) c 20) c 21) b 22) c 23) c 24) a 25) a 26) d 27) b 28) a 29) d 30) c 31) c 32) c 33) b 34) b 35) a 36) b 37) c 38) d 39) c 40) b 41) d 42) a 43) c 44) d 45) c 46) d 47) a 48) b 49) b

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50) a 51) b 52) a 53) a 54) a 55) b 56) c 57) d 58) b 59) b 60) d 61) a 62) b 63) d 64) d 65) b 66) b 67) d 68) a 69) d 70) b 71) c 72) d 73) a 74) b 75) b 76) d 77) a 78) a 79) c 80) a 81) b 82) a 83) c 84) c 85) d 86) a 87) b 88) b 89) a 90) b 91) c 92) c 93) b 94) b 95) c 96) c 97) b 98) a 99) a 100) a 101) a 102) b 103) a 104) d 105) b 106) d 107) c 108) b 109) b

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110) a 111) c 112) c 113) d 114) b