Deck 1: CLEP: Chemistry and Biology

Question 1

+ O₂(g) --> 2SO₃(g)
What is the correct rate law for this reaction?

A)r = k[SO₂][O₂]
B)r = k[SO₃]
C)r = k[SO₂]2[O₂]
D)r = k[SO₃]2
E)r = k[SO₃][SO₂][O₂]

Answer 1

A
When writing a rate law for a chemical reaction, use the concentrations of the reactants raised to the powers of their coefficients. The rate constant, k, is determined experimentally and cannot be determined with the information in this problem. Thus, the correct rate law is r = k[SO₂]2[O₂].

Question 2

Which of the following molecules exhibits resonance?

A)H₂O
B)CO₂
C)O₂
D)O₃
E)SO₂

Answer 2

D
Resonance occurs when two or more bonds show double bond character. This effect occurs when a double bond in either location is energetically equal. The best way to identify resonance is to draw Lewis structures. In the context of this question, O₃ is the only molecule to exhibit resonance.

Question 3

Cobalt has an atomic mass of 59 and an atomic number of 27. What does this information reveal about most cobalt atoms?

A)They contain more neutrons than protons.
B)They naturally have a net negative charge.
C)They attract protons more strongly than electrons.
D)They form ions with a charge of 127 in compounds.

Answer 3

A

Question 4

Three identical balloons each contain one mole of gas. One balloon contains oxygen, one contains nitrogen, and one contains argon. Which of the following changes in volume will happen if the balloons are placed in a warmer room?

A)The balloon with argon will decrease most in volume because argon is a noble gas.
B)All of the balloons will decrease in volume equally because the temperature increased.
C)The balloon with oxygen will increase most in volume because oxygen has the largest molecules.
D)All of the balloons will increase in volume equally because they have equal numbers of molecules.

Question 5

A student adds iron filings to a copper(II) chloride solution at room temperature. A balanced equation for the reaction that occurs is shown below. Fe_(s) + CuCL₂(aq) → FeCL₂(aq) + Cu_(s)
Which of the following changes would most likely increase the reaction rate?

A)using larger pieces of iron
B)performing the reaction in an ice bath
C)decreasing the volume of the CuCL₂ solution
D)increasing the concentration of the CuCL₂ solution

Question 6

The equation below shows the reaction of ammonia with water: NH₃(q) + H₂O(I) ↔ NH₄+(aq) + OH^-_(aq) According to the Brønsted-Lowry theory of acids and bases, which of the following is acting as the acid for the forward reaction?

A)NH₃
B)H₂O
C)NH₄+
D)OH^-

Question 7

Iron(II) chloride (FeCL₂) is a product of the reaction between iron metal (Fe) and hydrochloric acid (HCl), as shown in the equation below. Fe + 2HCl → FeCL₂ + H₂. What is the change in oxidation number of iron in this reaction?

A)from 0 to +2
B)from +1 to +2
C)from 0 to
D)from -1 to -2

Question 8

The reduction of carbon dioxide by hydrogen gas takes place at 420°C to produce water vapor and carbon monoxide. The equation for this reaction at equilibrium is shown below.
H_2(g) + CO_2(g) ↔ H₂O_(g)+ CO_(g).
Which of the following changes in concentration occur when more water vapor is added to the system under equilibrium conditions?

A)[H₂] decreases, [CO₂] decreases, [CO] increases
B)[H₂] decreases, [CO₂] decreases, [CO] increases
C)[H₂] increases, [CO₂] increases, [CO] increases
D)[H₂] increases, [CO₂] increases, [CO] increases

Question 9

A neutral atom has an outer shell electron configuration of 2s22p6. To which of the following groups of elements does it belong?

A)alkali metals
B)alkaline
C)halogens
D)noble gases

Question 10

Which of the following statements best explains why water has a high surface tension?

A)The force of attraction between neighboring polar water molecules is weak.
B)The force of attraction between neighboring polar water molecules is strong.
C)The force of attraction between neighboring nonpolar water molecules is weak.
D)The force of attraction between neighboring nonpolar water molecules is strong.

Question 11

The average distance between molecules always increases during which of the following phase changes?

A)gas to solid
B)liquid to gas
C)gas to liquid
D)liquid to solid

Question 12

Which of the following ideas was proposed by Niels Bohr?

A)Electrons occupy specific energy levels within an atom.
B)The nucleus of an atom contains neutrons as well as protons.
C)An atom is a solid sphere that cannot be separated into smaller parts.
D)An atom consists of negative charges embedded in a positively charged sphere.

Question 13

Carbon reacts with chlorine to form CCl4. What is the name of this compound?

A)carbon 4
B)1
C)tetracarbon chloride
D)carbon tetrachloride

Question 14

A walk -in cooler has a volume of 1.1 X 104 L. If the temperature inside the cooler is 3°C and the gas pressure is 1.0 atm, how many moles of gas are inside the cooler?

A)4.9 X 10² mol
B)4.5 X 10⁴ mol
C)2.5 X 10⁵ mol
D)6.0 X 10²³ mol

Question 15

Which of the following statements best explains why ionic solids dissolve in water?

A)Water has high surface tension.
B)Water is a highly polar molecule.
C)Water is more dense as a liquid than as a solid.
D)Water has a higher boiling point than predicted by its molar mass.

Question 16

The chemical equation below represents sulfur trioxide (SO₃) in the atmosphere mixing with rainwater to form sulfuric acid (H₂SO₄), which is a major component of acid rain:
SO₃(g) + H₂O(I) → H₂SO_4(I)
The molar mass of SO₃ is 80.1 g/mol and the molar mass of H₂SO₄ is 98.1 g/mol. How much H₂SO₄ is produced when 128.0 g of SO₃ mixes with rainwater?

A)98.1 g
B)105 g
C)128 g
D)157 g

Question 17

Which of the following statements explains why the human body produces chemical buffers?

A)Buffers maintain a constant pH in the blood.
B)Buffers dissolve salts and minerals in the blood.
C)Buffers decompose food molecules during digestion.
D)Buffers catalyze chemical reactions in the body cells.

Question 18

0 M solution of HCl is diluted to 1.0 M. How many milliliters of the 6.0 M solution would be used to prepare 100.0 mL of the diluted 1.0 M solution?

A)6 mL
B)17 mL
C)33 mL
D)100 mL

Question 19

After crude oil is pumped out of the ground, it must be processed in a "cracking tower." The tower separates it into less dense chemicals like butane and gasoline, and more dense chemicals like diesel fuel and tar. Based on this information, crude oil can best be classified as a

A)pure compound.
B)mixture of compounds.
C)mixture of pure elements.
D)solution of plasma and liquid.

Question 20

When a cup of hot chocolate cools from 90°C to 80°C, which of the following is happening to the molecules of the liquid?

A)Their rate of motion is decreasing.
B)Their valence electrons are being lost.
C)Their positions are becoming fixed in crystals.
D)Their average distance from adjacent molecules is increasing.

Question 21

Which of the following statements describes a gamma ray?

A)A gamma ray has no mass.
B)A gamma ray has a positive charge.
C)A gamma ray can be stopped by a sheet of paper.
D)A gamma ray can be converted into a beta particle.

Question 22

When a scuba diver is deep underwater and exhales, air bubbles form and rise to the surface of the water. Which of the following statements best describes what happens to the air bubbles as they rise to the surface?

A)The number of molecules in the bubbles increases, and the diameter of the bubbles increases.
B)The number of molecules in the bubbles decreases, and the diameter of the bubbles decreases.
C)The number of molecules in the bubbles remains the same, and the diameter of the bubbles increases.
D)The number of molecules in the bubbles remains the same, and the diameter of the bubbles decreases.

Question 23

1S22S22P63S23P64S1 is the electron configuration for which element?

A)aluminum (Al)
B)argon (Ar)
C)potassium (K)
D)sodium (Na)

Question 24

The equation below shows ammonia dissolving in water:
NH₃(aq) + H₂O(I) ↔ NH₄+(aq) + OH ^-_(aq)
Why is water considered an acid when ammonia is dissolved in it?

A)Water acts as a proton donor.
B)Water acts as a proton acceptor.
C)Water contains hydrogen atoms.
D)Water has a 2:1 ratio of hydrogen to oxygen.

Question 25

Which of the following elements has characteristics of some metals and also of some nonmetals?

A)antimony ( ₅₁Sb)
B)calcium ( ₂₀Ca)
C)sulfur (₁₆ S)
D)zinc ( ₃₀ Zn)

Question 26

Under certain conditions, solid magnesium (Mg) and solid sulfur (S) can combine and form magnesium sulfide (MgS). The oxidation -reduction reaction is shown below.Mg(s) + S(s) → MgS(s) Which of the following is the oxidation number for Mg in MgS in this reaction?

A)+1
B) -1
C)+2
D) -2

Question 27

A student adds 68.4 g of sucrose (C₁₂H₂₂O₁₁) to 750 mL of 20°C water. She stirs the solution until all of the sucrose crystals dissolve. She then transfers the solution to a volumetric flask and fills it to the 1.00 L mark with 20°C water. What is the molarity of the sucrose solution the student prepared?

A)0.20 M
B)0.70 M
C)1.0 M
D)6.8 M

Question 28

An unknown metal, X, combines with nitrogen to form the compound XN. Metal X also combines with oxygen to produce the compound X₂O₃. Metal X is most likely which of the following elements?

A)₃Li
B)₁₂Mg
C)₃₁Ga
D₅₀Sn

Question 29

00 kg sample of water (H₂O) contains 0.11 kg of hydrogen (H) and 0.89 kg of oxygen (O). According to the law of constant composition, how much hydrogen and oxygen would a 1.5 kg sample of water contain?

A)0.11 kg H and 0.89 kg O
B)0.17 kg H and 1.34 kg O
C)0.22 kg H and 1.78 kg O
D)1.34 kg H and 0.17 kg O

Question 30

Which statement below best describes what happens when sodium chloride, NaCl, is dissolved in water?

A)The NaCl separates into Na+ and Cl ^-ions.
B)The NaCl separates into uncharged Na and Cl.
C)The NaCl reacts with water to form NaH and HCl.
D)The NaCl reacts with water to form NaOH and CL₂.

Question 31

Black powder was used as a propellant for fireworks for centuries. One of the components of black powder is potassium nitrate (KNO₃). Black powder containing 1 mol of KNO₃ releases 289 kJ of heat during combustion. The molar mass of KNO₃ is 101 g/mol. How much heat is released if a firework contains 250 g of KNO₃?

A)117 kJ
B)715 kJ
C)29, 189 kJ
D)72, 250 kJ

Question 32

50 L container at 305 K holds a 0.22 g sample of carbon dioxide gas (CO₂). Assuming ideal gas behavior, what is the pressure, in kilopascals, exerted by the gas?

A)23 kPa
B)25 kPa
C)41 kPa
D)67 kPa

Question 33

Bismuth -210 (210/83 Bi) decays directly to polonium-210 (210/84 Po). Which of the following must be emitted during this radioactive decay?

A)alpha particle
B)beta particle
C)neutron
D)proton

Question 34

A chemical reaction is shown below:
Zn(s) + 2H+(aq) → Zn₂+(aq) + H_2(g)
Which of the following statements best explains why this chemical reaction is an oxidation- reduction reaction?

A)Zn reacts under basic conditions.
B)Zn dissolves in an aqueous solution.
C)Zn and H+ undergo a change of state.
D)Zn loses electrons and H+ gains electrons.

Question 35

A sample of nitrogen (N2) gas in a10.0 L container has a pressure of 1.0 atm at 297 K. Assuming ideal gas behavior, what will the pressure be if the same amount of nitrogen gas is put into a 5.0 L container at 297 K?

A)0.40 atm
B)0.50 atm
C)2.0 atm
D)2.5 atm

Question 36

The atomic theories of Dalton, Thomson, Rutherford, and Bohr all support which of the following statements?

A)Atoms are mostly composedof empty space.
B)All matter is composed of tiny, discrete particles called atoms.
C)Electrons orbit the nucleus of an atom at distinct energy levels.
D)Atoms are composed of positivelyand negatively charged particles.

Question 37

Two compounds that contain the elements carbon and chlorine are carbon tetrachloride (CCl4) and chloroform (CHCl3). Which of the following statements describes the geometry around carbon in these two compounds?

A)CCl4 and CHCl3 have bent geometries.
B)CCl4 and CHCl3 have tetrahedral geometries.
C)CCl4 has linear geometry and CHCl3 has bent geometry.
D)CCl4 has tetrahedral geometry and CHCl3 has trigonal planar geometry.

Question 38

Why is sulfuric acid (H₂SO4) considered a Brønsted acid?

A)It has a pH greater than 7.
B)It is able to donate protons.
C)It contains a hydroxide ion.
D)It reacts with hydronium ions.

Question 39

Palmitic acid, a component of most animal fats, has the molecular formula CH₃(CH₂)14COOH. Which of the following is the empirical formula for palmitic acid?

A)CHO
B)C₃H₆O₂
C)C8H16O
D)C₁₆H₃2O₂

Question 40

Hydrogen peroxide decomposes according to the equation below:
2H₂O₂(aq) ↔ O₂(g) + 2H₂O_(I)
Which of the following actions will slow down the rate of this reaction?

A)adding a catalyst
B)adding more H₂O₂
C)decreasing the temperature
D)removing O₂ that is produced

Question 41

A sealed flask contains 1.3 X 10²⁵ . molecules of CO₂. How many moles of CO₂ are in the flask?

A)0.046 mol
B)22 mol
C)3.0 X 10²³ mol
D)7.8 X 10⁴⁸ mol

Question 42

Which element has the electron configuration 1S22S2P3?

A)boron
B)nitrogen
C)fluorine
D)phosphorus

Question 43

The compound Mg(OH)2 is classified as an Arrhenius base because, when the compound dissolves in water, there is an increase in the concentration of which of the following ions?

A)hydrogen ions
B)hydroxide ions
C)magnesium ions
D)oxide ions

Question 44

When pure N2O5 is heated under certain conditions, O₂ and NO₂ are produced. What type of reaction is this?

A)combustion
B)decomposition
C)double displacement
D)synthesis (combination)

Question 45

The equation below shows the reaction of chloroform (CHCl₃) with hydrogen (H₂) to produce methane (CH₄) and chlorine (CL₂):
2CHCl₃(g) + 3H_2(g) + heat ↔ 2CH₄(g) + 3CL₂(g)
Which of the following changes will shift the equilibrium to the right, producing more methane?

A)raising the temperature of the reaction
B)lowering the concentration of hydrogen
C)increasing the total pressure of the gases
D)increasing the volume of the reaction vessel

Question 46

What is the volume of 0.25 mol of ammonia gas (NH₃) at 1.00 atmand 273 K?

A)0.33 L
B)5.6 L
C)95 L
D)1530 L

Question 47

Barium and iodine combine to form an ionic compound. What is the chemical formula for this compound?

A)BaI
B)BaI₂
C)Ba₂I
D)Ba₂I₂

Question 48

A crystal of table salt (NaCl) is dissolved in water. Which of the following statements explains why the dissolved salt does not recrystallize as long as the temperature and the amount of water stay constant?

A)Na+ and Cl
B)Water molecules surround the Na+ and Cl
C)Na+ and Cl
D)Water molecules chemically react with the Na+ and Cl

Question 49

In the reaction of hydrobromic acid (HBr) and ammonia (NH₃), ammonia acts as a Brønsted base. Which of the following ions is formed?

A)N+
B)NH₂
C)NH₂
D)NH₄₊

Question 50

Calcium combines with boron, as represented by the chemical equation below:
Ca + 6B → CaB6
What is the minimum amount of calcium, in grams, that could completely react with 54.0 g of boron?

A)9.00 g
B)33.4 g
C)87.4 g
D)241 g

Question 51

Which of the following elements has an electron configuration of ls22s22p63s23p1?

A)lithium
B)aluminum
C)phosphorus
D)calcium

Question 52

In 2006, scientists discovered fossilized skeletons of an animal with several interesting features. Fossil evidence indicated that the animal not only had scales, fins, and gills, but also had lungs, a full set of ribs, and limb bones arranged to support the animal's weight. The illustration below shows what the animal, called Tiktaalik, probably looked like based on the fossil evidence.Which of the following statements best explains why the Tiktaalik fossils are an important piece of evidence for evolution?

A)They include skeletons of both males and females.
B)They are complete skeletons of a carnivorous animal.
C)They allow scientists to estimate the animal's lifespan.
D)They show a transitional form between fish and land-dwelling vertebrates.

Question 53

Mallory has four aquatic plants of the same size and species. She submerges each plant in a separate beaker filled with 200 mL of water. She then sets each beaker under a different intensity of light. Mallory observes that, of the four plants, the plant in the beaker under the most intense light gives off the most gas bubbles in a 20 min period.Which of the following statements best explains Mallory's observations?

A)Cells decompose most quickly under the most intense light.
B)Water evaporates from plants fastest under the most intense light.
C)Photosynthesis occurs at the highest rate under the most intense light.
D)Gases in the leaves of plants expand most under the most intense light.