Chemistry 2 exam

What is the balanced nuclear equation for the beta emission of the radioisotope strontium-90?

90-38 Sr --> 90-38 + 0- -1 e

How many protons and neutrons are in S? A) 16 p and 34 n B) 16 n and 34 p C) 16 n and 18 p D) 16 p and 18 n E) none of the above

D) 16 p and 18 n

What are the two half reactions that show how many electrons are gained or lost by each species in the reaction: Ni2+(aq) + Mg(s) → Ni(s) + Mg2+(aq)? A. Ni2+(aq) + e- → Ni(s) and Mg(s) → Mg2+(aq) + e- B. Ni2+(aq) + 2e- → Ni(s) and Mg(s) → Mg2+(aq) + e- C. Ni2+(aq) → Ni(s) + 2e- and Mg(s) + 2e- → Mg2+(aq) D. Ni2+(aq) → Ni(s) + e- and Mg(s) + e- → Mg2+(aq) E. Ni2+(aq) + 2e- → Ni(s) and Mg(s) + 2e- → Mg2+(aq)

None of the above

Which type of radiation has the largest mass? A) An alpha particle B) A gamma ray C) A positron D) A beta particle E) none of the above

A) An alpha particle

For the chemical reaction system described by the diagram below, which statement is true? A) The activation energy for the reverse reaction is greater than the activation energy for the forward reaction. B) The activation energy for the forward reaction is greater than the activation energy for the reverse reaction. C) At equilibrium, the activation energy for the forward reaction is equal to the activation energy for the reverse reaction. D) The forward reaction is endothermic E) The reverse reaction is exothermic.

A) The activation energy for the reverse reaction is greater than the activation energy for the forward reaction.

What is the molarity of an HCl solution if 43.6 mL of a 0.125 M KOH solution are needed to titrate a 25.0 mL sample of the acid according to the equation below? KOH(aq) + HCl(aq) → H2O(l) + KCl(aq) A. 0.218 M HCl B. 0.573 M HCl C. 0.0717 M HCl D. 4.58 M HCl E. 1.74 M HCl

A. 0.218 M HCl

A sample of neon gas has a volume of 5.0 mL at a pressure of 1.50 atm. What is the pressure exerted by the gas if the volume is increased to 30.0 mL, at constant temperature? A. 0.25 atm B. 9.0 atm C. 1.5 atm D. 0.21 atm E. 7.5 atm

A. 0.25 atm

A sample of gas contains four gases with the following partial pressures: He (113 mm Hg), Ne (184 mm Hg), Ar (35 mm Hg), and Xe (445 mm Hg). What is the total pressure of the sample? A. 777 mm Hg B. 760. mm Hg C. 445 mm Hg D. 332 mm Hg E. None of the above

A. 777 mm Hg

Which of the following statements concerning a solution is NOT true? A. A solution is a heterogeneous mixture of two or more pure substances. B. A solution is composed of a solvent and one or more solutes; the solute(s) dissolve in the solvent. C. A solution has its components uniformly distributed. D. A solution is likely to form when the solute(s) and the solvent have similar polarities. E. All of the above are NOT true F. All of the above are TRUE

A. A solution is a heterogeneous mixture of two or more pure substances.

Identify the species that is oxidized and the species that is reduced in the reaction: 2 I- + Cl2 → 2 Cl- + I2 A. I- is oxidized and Cl2 is reduced. B. Cl2 is oxidized and I- is reduced. C. I2 is oxidized and Cl- is reduced. D. Cl2 is oxidized and Cl- is reduced. E. I2 is oxidized and I- is reduced.

A. I- is oxidized and Cl2 is reduced.

What is the missing particle? 231-90 Th -> _____ + 231-89 Ac A. positron B. beta particle C. alpha particle D. gamma particle E. none of the above

A. positron

Pure water cannot conduct electricity so why do we have to be careful with electrical appliances near water? A) OSHA regulations B) Water always has some ions dissolved in it. C) Water can be broken down by electricity. D) Water dissociates fully into its ions. E) none of the above

B) Water always has some ions dissolved in it.

What is the concentration of a solution formed by diluting 25.0 mL of a 3.2 M NaCl solution to 135.0 mL? A. 17 M NaCl B. 0.59 M NaCl C. 0.50 M NaCl D. 2.7 M NaCl E. None of the above

B. 0.59 M NaCl

A 54.2 L sample of gas at 115 K is heated to 345 K, at constant pressure. What volume does the gas now occupy? A. 2.15 * 10^6 L B. 163 L C. 18.1 L D. 732 L E. None of the above

B. 163 L

What is the volume of 62.3 g of nitrogen gas (N2) at STP? A. 22.4 L B. 49.8 L C. 99.6 L D. 2.78 L E. None of the above

B. 49.8 L

Which type of radiation has the greatest penetrating power? A. An alpha particle B. A gamma ray C. A beta particle D. All of these have the same penetrating power. E. None of the above

B. A gamma ray

Which of the following statements concerning solution concentration is NOT true? A. An unsaturated solution contains less than the maximum amount of solute that can be dissolved in the solvent. B. A saturated solution contains more than 100 g of dissolved solute. C. A solution can be made less concentrated by adding additional solvent. D. The number of moles of solute present in exactly one liter of solution is referred to as the solution's molarity. E. All of the above are NOT TRUE F. All of the above are TRUE

B. A saturated solution contains more than 100 g of dissolved solute.

Which ionic compound is not soluble in water? A. NaCl B. AgCl C. (NH4)2SO4 D. Ca(CH3CO2)2 E. BaBr2

B. AgCl

Write a balanced chemical equation for the reaction of acetone (C3H6O) with oxygen (O2) to form carbon dioxide (CO2) and water (H2O) A. C3H6O + O2 → CO2 + H2O B. C3H6O + 4 O2 → 3 CO2 + 3 H2O C. 3 CO2 + 3 H2O → C3H6O + 4 O2 D. 6 C3H6O + 8 O2 → 6 CO2 + 6 H2O E. None of the above are correct

B. C3H6O + 4 O2 → 3 CO2 + 3 H2O

Which species can act as a Brønsted-Lowry acid? A. CO32- B. HBr C. Br2 D. LiOH E. None of the above

B. HBr

An alpha particle is a high-energy particle that contains A. one proton and one neutron. B. two protons and two neutrons. C. one electron. D. one proton. E. none of the above

B. two protons and two neutrons.

Which of the following is NOT an acid-base conjugate pair? A) H2CO3 and HCO3- B) H2O and OH C) H2S and OH D) NH4+and NH3 E) none of the above

C) H2S and OH

The following reaction: 235- 92U + 1 0n → 90-38Sr + 143 -54Xe + 31 0n represents: A) alpha decay B) positron decay C) the nuclear equation is an example of nuclear fission. D) the nuclear equation is an example of nuclear fusion. E) none of the above

C) the nuclear equation is an example of nuclear fission.

How many moles are contained in 5.33 L of O2 at standard temperature and pressure? A. 5.33 mol of O2 B. 1.00 mol of O2 C. 0.238 mol of O2 D. 22.4 mol of O2 E. 4.20 mol of O2

C. 0.238 mol of O2

A scuba diver typically begins a dive with a compressed air tank at 2,350 psi. What is this pressure expressed in units of mm Hg? A. 160. mm Hg B. 3.09 mm Hg C. 1.21 *10^5 mm Hg D. 1.79 * 10^6 mm Hg E. 45.5 mm Hg

C. 1.21 *10^5 mm Hg

Consider the reaction: 2Al(OH)3 + 3H2SO4 → Al2(SO4)3 + 6H2O. How many grams of Al2(SO4)3 are generated when 152 g of H2SO4 reacts? A. 530. g of Al2(SO4)3 B. 1590 g of Al2(SO4)3 C. 177 g of Al2(SO4)3 D. 43.6 g of Al2(SO4)3 E. 131 g of Al2(SO4)3

C. 177 g of Al2(SO4)3

What is the molarity of a solution made by dissolving 3.09 moles of NaCl in 1.50 L of solution? A. 4.64 M NaCl B. 4.85 M NaCl C. 2.06 M NaCl D. 0.673 M NaCl E. None of the above

C. 2.06 M NaCl

The temperature of a 1.00-L gas sample at 30.0 °C and 1.75 atm is changed to 225 °C. What is the final pressure of the system, at constant volume? A. 20.0 atm B. 0.200 atm C. 2.88 atm D. 0.427 atm E. None of the above

C. 2.88 atm

What is the pH of a peach with a [OH- ] = 3.2 x 10-11 M [OH- ]? A. 11.32 B. 10.49 C. 3.51 D. 3.20 E. None of the above

C. 3.51

How many iron atoms are in 0.32 mol of Fe2O3? A. 6.02 x 1023 iron atoms B. 3.9 iron atoms C. 3.9 x 1023 iron atoms D. 1.9 x 1023 iron atoms E. 1.1 x 10-24 iron atoms

C. 3.9 x 1023 iron atoms

How many milliliters of 0.653 M NaOH are needed to neutralize 25.0 mL of a 1.02 M HBr solution? The neutralization reaction is NaOH(aq) + HBr(aq) H2O(l) + NaBr(aq) A. 16.0 mL NaOH B. 25.5 mL NaOH C. 39.1 mL NaOH D. 16.3 mL NaOH E. None of the above

C. 39.1 mL NaOH

Ammonia gas decomposes according to the equation: 2NH3(g) → N2(g) + 3H2(g) If 15.0 L of nitrogen is formed at STP, how many liters of hydrogen Gas (H2) will be produced. (also measured at STP)? A. 15.0 L B. 30.0 L C. 45.0 L D. 90.0 L E. not enough information

C. 45.0 L

A solution is made by dissolving 3.88 g of NaCl in enough water to make 67.8 mL of solution. What is the concentration of sodium chloride in units of weight/volume percent? A. 5.41% (w/v) NaCl B. 94.3% (w/v) NaCl C. 5.72% (w/v) NaCl D. 0.0572% (w/v) NaCl E. None of the above

C. 5.72% (w/v) NaCl

Which solution containing an equal number of moles of each of the substances is a buffer? A. HCl and NaCl B. HNO2 and HNO3 C. CH3COOH and NaCH3COO¯ D. H2CO3 and CO3 2- E. More than one of the solutions is a buffer.

C. CH3COOH and NaCH3COO¯

Which substance is a nonelectrolyte? A. NaCl B. (NH4)2SO4 C. H2O2 D. KOH E. All are nonelectrolytes F. None are nonelectrolytes

C. H2O2

What is the balanced equation for the acid-base reaction of nitrous acid with lithium hydroxide hydroxide? A. LiOH(aq) + HNO3(aq) H2O(l) + LiNO3(aq) B. Li(OH)2(aq) + 2HNO3(aq) 2H2O(l) + Li(NO3) (aq) C. LiOH(aq) + HNO2(aq) H2O(l) + LiNO2(aq) D. 2LiOH(aq) + H2NO2(aq) 2H2O(l) + Li2NO2(aq) E. None of the above

C. LiOH(aq) + HNO2(aq) H2O(l) + LiNO2(aq)

What does it mean if a substance is described as being radioactive? A. The substance was exposed to radiation that was given off by a decaying nucleus. B. The substance readily absorbs energy from the radio frequency region of the electromagnetic spectrum. C. The substance emits high energy particles or rays from its unstable nucleus. D. The substance is extremely small and special radiomicroscopes are necessary to view it. E. none of the above

C. The substance emits high energy particles or rays from its unstable nucleus.

In a nuclear equation: A) the daughter nuclide appears on the right-side of the arrow. B) the sum of the atomic numbers on both sides must be equal. C) the sum of the mass numbers on both sides must be equal. D) all of the above E) none of the above

D) all of the above

An endothermic reaction causes the surroundings to A) warm up. B) become acidic. C) condense. D) decrease in temperature. E) release CO2.

D) decrease in temperature.

The following reaction: 2 1H + 3 1H → 4 2He + 1 0n represents: A) neutron capture B) alpha decay C) the nuclear equation is an example of nuclear fission. D) the nuclear equation is an example of nuclear fusion. E) none of the above

D) the nuclear equation is an example of nuclear fusion.

Which solution has the highest pH? A. 4.3 x 10-8 M H3O+ B. 1.0 x 10-7 M H3O+ C. 5.1 x 10-2 M H3O+ D. 1.9 x 10-8 M H3O+ E. 1.0 x 10-2 M H3O+

D. 1.9 x 10-8 M H3O+

in the chemical equation 2Co(NO3)3 + 3(NH4)2S --> Co2S3 + 6 NH4NO3, how many nitrogn atoms are on each side of the equation? A. 2 B. 3 C. 6 D.12 E. 16

D. 12

A weather balloon contains 233 L of helium at 22.0 °C and 760. mm Hg. What is the volume of the balloon when it ascends to an altitude where the temperature is -54.0 °C and a pressure of 511 mm Hg? A. 2.24 * 10^7 L B. 467 L C. 116 L D. 257 L E. None of the above

D. 257 L

Which ionic compound is soluble in water? A. PbBr2 B. Fe(OH)3 C. BaSO4 D. Ca(NO3)2 E. More than one of the ionic compounds is soluble in water.

D. Ca(NO3)2

Which species is a diprotic acid? A. Mg(OH)2 B. CH3COOH C. H2 D. H2CO3 E. None of the above

D. H2CO3

Which assumption is not part of the kinetic-molecular theory of gases? A. A gas consists of particles that move randomly and rapidly. B. The size of gas particles is small compared to the space between the particles. C. Because the space between gas particles is large, gas particles exert no attractive forces on each other. D. The kinetic energy of gas particles does not change with increasing temperature. E. When gas particles collide with each other, they rebound and travel in new directions.

D. The kinetic energy of gas particles does not change with increasing temperature.

Given the reaction 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) E. None of the above

D. increase the frequency of collisions between A2(g) and B2(g)

Nonpolar compounds are soluble in A. ionic compounds. B. electrolytes. C. polar solvents. D. nonpolar solvents. E. none of the above

D. nonpolar solvents.

How many carbon atoms are in 77.28 g of ethane (C2H6)? A. 2.570 carbon atoms B. 5.140 carbon atoms C. 1.238 * 10^25 carbon atoms D. 1.548 * 10^24 carbon atoms E. 3.094 * 10^24 carbon atoms

E. 3.094 * 10^24 carbon atoms

Which substance is an electrolyte? A. NaCl B. (NH4)2SO4 C. LiBr D. KOH E. All of the above are electrolytes

E. All of the above are electrolytes