Question 1

Which of the following statements describes a gamma ray?

Accepted Answer

Gamma rays have no mass and are a form of electromagnetic radiation, similar to X-rays but with higher energy.

Question 2

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?

Accepted Answer

The number of molecules in the bubbles remains the same as they rise, but the pressure decreases as the bubbles ascend to the surface, allowing the bubbles to expand and thus increase in diameter.

Question 3

1S22S22P63S23P64S1 is the electron configuration for which element?

Accepted Answer

The electron configuration 1S22S22P63S23P64S1 corresponds to potassium (K), which has an atomic number of 19.

Question 4

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?

Accepted Answer

Water is considered an acid in this reaction because it donates a proton (H+) to ammonia, forming NH4+ and OH-.

Question 5

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

Accepted Answer

Antimony (Sb) is classified as a metalloid, which means it has properties of both metals and nonmetals. This makes it the correct choice for an element with characteristics of some metals and also of some nonmetals.

Question 6

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?

Accepted Answer

In magnesium sulfide (MgS), magnesium (Mg) has an oxidation number of +2. This is because magnesium typically loses two electrons to achieve a stable electron configuration, resulting in a +2 charge.

Question 7

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?

Accepted Answer

The molarity (M) is calculated by dividing the moles of solute by the liters of solution. The molar mass of sucrose is approximately 342.3 g/mol. Thus, 68.4 g of sucrose is 0.2 moles (68.4 g / 342.3 g/mol). The total volume of the solution is 1.00 L, so the molarity is 0.2 moles / 1.00 L = 0.20 M.

Question 8

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?

Accepted Answer

Gallium (Ga) forms GaN with nitrogen and Ga2O3 with oxygen, matching the given compounds.

Question 9

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?

Accepted Answer

The law of constant composition states that a chemical compound always contains its component elements in fixed ratio by mass and does not depend on its source and method of preparation. Therefore, to find the amount of hydrogen and oxygen in a 1.5 kg sample of water, we scale the amounts in the original 1.0 kg sample by 1.5. This gives 0.11 kg * 1.5 = 0.165 kg of hydrogen (rounded to 0.17 kg) and 0.89 kg * 1.5 = 1.335 kg of oxygen (rounded to 1.34 kg).

Question 10

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

Accepted Answer

When sodium chloride (NaCl) is dissolved in water, it dissociates into its constituent ions, Na+ and Cl-, due to the polar nature of water molecules that surround and stabilize these ions.

Question 11

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?

Accepted Answer

First, calculate the number of moles in 250 g of KNO₃: $ \frac{250 \, \text{g}}{101 \, \text{g/mol}} = 2.475 \, \text{moles} $. Since 1 mole releases 289 kJ, $ 2.475 \, \text{moles} \times 289 \, \text{kJ/mole} = 715.275 \, \text{kJ} $, which rounds to 715 kJ.

Question 12

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?

Accepted Answer

To find the pressure exerted by the gas, we can use the ideal gas law equation, PV = nRT, where P is the pressure, V is the volume, n is the number of moles of gas, R is the ideal gas constant, and T is the temperature in Kelvin. First, we need to convert the mass of CO2 to moles. The molar mass of CO2 is 44.01 g/mol (12.01 for C + 2*16.00 for O), so 0.22 g of CO2 is 0.22 g / 44.01 g/mol = 0.005 moles. The volume is given as 50 L (which is 0.05 m^3, since 1 m^3 = 1000 L), and the temperature is 305 K. The ideal gas constant R can be used in various units, but for this calculation, we'll use 8.314 (m^3·kPa)/(K·mol). Plugging the values into the ideal gas law equation gives:P = nRT/V = (0.005 moles * 8.314 kPa·m^3/(K·mol) * 305 K) / 0.05 m^3 = 25.4 kPaTherefore, the pressure exerted by the gas is closest to 25 kPa.

Question 13

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

Accepted Answer

During the decay of Bismuth-210 to Polonium-210, a beta particle is emitted. This is because the atomic number increases by 1 (from 83 to 84), indicating the conversion of a neutron into a proton and the emission of a beta particle (electron).

Question 14

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?

Accepted Answer

In an oxidation-reduction (redox) reaction, one species loses electrons (oxidation) while another gains electrons (reduction). In the given reaction, Zn loses electrons to form Zn^2+, and H+ gains electrons to form H2 gas, making statement D correct.

Question 15

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?

Accepted Answer

According to Boyle's Law (P1V1 = P2V2), if the temperature and the amount of gas remain constant, the pressure of a gas is inversely proportional to its volume. Therefore, halving the volume from 10.0 L to 5.0 L doubles the pressure from 1.0 atm to 2.0 atm.

Question 16

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

Accepted Answer

John Dalton was an English chemist, physicist, and meteorologist. He is best known for introducing the atomic theory into chemistry and his research into color blindness, sometimes referred to as Daltonism. 
Dalton's Theory's 5 Key Points
1. Everything is composed of atoms, indivisible building blocks of matter. Atoms cannot be created, subdivided, or destroyed.
2. All atoms of a specific element are identical.
3. Atoms of different elements vary in size and mass.
4. Compounds are produced through different whole-number combinations of atoms (Dalton's "compounds" are now referred to "molecules").
5. A chemical reaction results in the rearrangement of atoms in the reactant and product compounds.
Since Dalton's conclusions are based on an empirical analysis of experimental results, this is the first officially scientific atomic theory. Dalton's work led him to develop the Law of Conservation of Mass (matter cannot be created nor destroyed) and the Law of Constant Composition (elements combine in a fixed ratio to make up molecules). 
Dalton's atomic theory expanded in 1897 when English physicist J.J. Thomson began experimenting with a cathode ray tube. Using the cathode ray tube, Thomson discovered electrons, which are tiny particles with a negative electric charge. 
The atomic theory was further expanded in 1911 when Thomson's colleague Ernest Rutherford began experimenting with alpha particles to probe the atomic structure of gold foil. In his now-famous Gold Foil Experiment, Rutherford saw that while most alpha particles passed right through the gold foil, a few deflected to the side, and some even bounced back. This experiment provided Rutherford with evidence that the majority of an atom's mass is contained in the center of the atom. Rutherford combined this discovery with Thomson's idea of electrons to develop a better model for particles wherein much smaller negatively charged electrons surround a large, positively charged nucleus, much like planets around a sun.

Question 17

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?

Accepted Answer

CCl4 has a tetrahedral geometry because it has four bonds and no lone pairs on the carbon atom. CHCl3 also has a tetrahedral geometry because it has three bonds and one lone pair on the carbon atom, which still results in a tetrahedral electron pair geometry; the molecular shape is described as "trigonal pyramidal," but the question specifically asks about the geometry around carbon, referring to the electron pair geometry.

Question 18

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

Accepted Answer

Sulfuric acid is considered a Brønsted acid because it can donate protons (H+ ions) to other substances.

Question 19

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?

Accepted Answer

The answer of Palmitic acid, a component of most animal...

Question 20

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?

Accepted Answer

Decreasing the temperature slows down the rate of most chemical reactions by reducing the kinetic energy of the molecules involved, which decreases the frequency and energy of collisions between reactant molecules.

Quiz 1: CLEP: Chemistry and Biology

Which of the following statements describes a gamma ray?

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?

1S22S22P63S23P64S1 is the electron configuration for which element?

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?

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

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?

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?

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?

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

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?

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 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 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?

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

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?

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

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?

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?

Quiz 1: CLEP: Chemistry and Biology

Which of the following statements describes a gamma ray?

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?

1S22S22P63S23P64S1 is the electron configuration for which element?

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?

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

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?

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?

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?

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

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?

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 chemical reaction is shown below: Zn(s) + 2H+(aq) → Zn2+(aq) + H2(g) Which of the following statements best explains why this chemical reaction is an oxidation- reduction reaction?

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?

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

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?

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

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?

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?

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?

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?

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?

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 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?

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

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?

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?