AP Chem sem 2 final (AP Test)

Gases generated in a chemical reaction are sometimes collected by the displacement of water, as shown above. Which of the following gases can be quantitatively collected by this method. A. H₂ B. CO₂ C. HCl D. SO₂ E. NH₃

A

Which has two lone pairs of electrons A. H₂O B. NH₃ C. BH₃ D. CH₄ E. SiH₄

A

2NH₃ (g) → 3H₂ (g) + N₂ (g) ∆H°₂₉₈ = 92 kj/mol according to the information above what is the standard enthalpy of formation, ∆H°f, for NH₃(g) at 298 K? A. -92 kj/mol B. -46 kj/mol C. 46kj/mol D. 92kj/mol E. 184kj.mol

B

Atoms of Mg combine with atoms of F to form a compound. Atoms of which of the following elements combine with atoms of F in the same ratio? A. Li B. Ba C. Al D. Cl E. Ne

B

HSO₄⁻(aq) + CO₃²⁻(aq) ⇌ SO₄²⁻ (aq) + HCO₃⁻(aq) The reaction represented above is observed to proceed spontaneously to the right in aqueous solution. in this system the strongest base is. A. SO₄⁻²(aq) B. CO₃²⁻(aq) C. H₂O(l) D. HCO₃⁻(aq) E. HSO₄⁻(aq)

B

In which flask do the molecules have the greatest average speed? A. N₂, 30°C, 1 atm B. N₂, 50°C, .5 atm C. O₂, 40°C, 2 atm D. O₂, 50°C, 1 atm E. O₂, 40°C, .05 atm

B

LiHCO₃(aq) + H₂SO₄ (aq) →Li₂SO₄(aq) + H₂O(l) + CO₂(g) when the equation above is balanced and the coefficients are reduced to the lowest whole-number terms, what is the coefficient of H₂O(l)? A. 1 B. 2 C. 3 D. 4 E. 5

B

The reaction between a Bronsted-Lowry acid and a Bronsted-Lowery base. A. 2C₆H₆(l) + 15O₂(g)→ 12CO₂(g) + 6H₂O(l) B. C₂H₃O₂⁻(aq) + 4Co²⁺(aq) → HC₂H₃O₂ (aq) + H₂O(l) C. 4H⁺(aq) + 4 Co²⁺(aq)+O₂(g) + 24 NH₃ (aq)→ 4Co(NH₃)₆³⁺ + 2H₂O (l) D. CaCO₃(s) →CaO(s) + CO₂(g) E. 2H₂O₂ (l) → O₂(g) + 2H₂O(l)

B

Which flask contains the smallest number of moles of gas? A. N₂, 30°C, 1 atm B. N₂, 50°C, .5 atm C. O₂, 40°C, 2 atm D. O₂, 50°C, 1 atm E. O₂, 40°C, .05 atm

B

Which has a trigonal-pyramidal A. H₂O B. NH₃ C. BH₃ D. CH₄ E. SiH₄

B

A .10 M solution of a weak monoprotic acid has a pH equal to 4.0. the ionization constant, Ka, of the acid is. A. 1 x 10⁻³ B. 1 x 10⁻⁴ C. 1 x 10⁻⁷ D. 1 x 10⁻⁸ E. 1 x 10⁻⁹

C

A 2L sample of N₂(g) and a 1 L sample of Ar(g), each originally at 1 atm and 0°C, are combined in a 1 L tank. if the temperature is held constant, what is the total pressure of the gases in the tank. A. 1 atm B. 2 atm C. 3 atm D. 4 atm E. 5 atm

C

Which flask contains the sample with the greatest density? A. N₂, 30°C, 1 atm B. N₂, 50°C, .5 atm C. O₂, 40°C, 2 atm D. O₂, 50°C, 1 atm E. O₂, 40°C, .05 atm

C

Which has a central atom with less than an octet of electrons? A. H₂O B. NH₃ C. BH₃ D. CH₄ E. SiH₄

C

Which is predicted to have the largest bond angle A. H₂O B. NH₃ C. BH₃ D. CH₄ E. SiH₄

C

C₃H₈ (g) 5O₂ (g) → 3CO₂(g) + 4H₂O(l) In the reaction represented above, what is the total number of moles of reactants consumed when 1.00 mole of CO₂(g) is produced? A) .33 mol B) 1.33 mol C) 1.50 mol D) 2.00 mol E) 6.00 mol

D

For an experiment, a student needs 100.0 mL of .4220 M NaCl, if the students start with NaCl(s) and distilled water, which of the following pieces of laboratory glassware should the students use to prepare the solution with the greatest accuracy? A. 25mL volumetric pipet B. 100mL Erlenmeyer flask C. 100 mL graduated cylinder D. 100 ml Volumetric flask E. 1 L beaker

D

H₂ + F₂ → 2HF in the reaction represented above what mass of HF is produced by the reaction of 3.0 x 10²³ moles of H₂ with excess F₂? (assume the reaction goes to completion) A. 1.0g B. 4.0g C. 10.0g D. 20.0g E. 40.0g

D

Which of the following molecules contains polar covalent bonds but is a nonpolar molecule? A. CH₃Cl B. CH₂Cl₂ C. NH₃ D. CCl₄ E. N₂

D

A .20 mol sample of MgCl₂(s) and a .10 mol sample of KCl(s) are dissolved in water and diluted to 500 mL. What is the concentration of Cl⁻in the solution? A) .15M B) .30M C) .50M D) .60M E) 1.0M

E

C₂H₄(g) is reduced by H₂(g) in the presence of a solid platinum catalyst, as represented by the equation above. Factors that could affect the rate of the reaction include which of the following? I. Changes in the partial pressure of H₂(g) II. Changes in the particle size of the platinum catalyst. III. Changes in the temperature of the reaction system. A. III B. I and II only C. I and III only D. II and III only E. I, II, and III only

E

For which of the following reaction mixtures at equilibrium would reducing the volume of the container at constant temperature cause the equilibrium to shift toward the products? A. SrCO₃(s) ⇌ SrO(s) + CO₂ (g) B. C(s) + CO₂(g) ⇌ 2CO(g) C. CO(g) + H₂O(g) ⇌ CO₂(g) +H₂(g) D. PCl₅(g) ⇌ PCl₃(g) + Cl₂(g) E. 2NO₂ (g) ⇌ N₂O₄ (g)

E

The reaction in which a single species is both oxidized an reduced A. 2C₆H₆(l) + 15O₂(g)→ 12CO₂(g) + 6H₂O(l) B. C₂H₃O₂⁻(aq) + 4Co²⁺(aq) → HC₂H₃O₂ (aq) + H₂O(l) C. 4H⁺(aq) + 4 Co²⁺(aq)+O₂(g) + 24 NH₃ (aq)→ 4Co(NH₃)₆³⁺ + 2H₂O (l) D. CaCO₃(s) →CaO(s) + CO₂(g) E. 2H₂O₂ (l) → O₂(g) + 2H₂O(l)

E

Which element contains an element in a +1 oxidation state at 25°C and 1.0 atm. A. CO₂ B. PbO₂ C. CaO D. N₂O₅ E. Cu₂O

E

Which of the following elements has the largest first ionization energy? A. Li B. Be C. B D. C E. N

E

Which of the folowwing lists the substances F₂, HCl, and HF in order of increasing boiling point? A. HF< HCl < F₂ B. HF< F₂ < HCl C. HCl< F₂ < HF D. HCl < HF < F₂ E. F₂ < HCl < HF

E