CHEM1314 Exam 2 Review

Moles & Composition

Chemical Reactions

Solutions & Electrolytes

Redox

Stoichiometry

100

Select the chemical formula that is not an empirical formula.

a) P₂O₅

b) C₃H₈

c) BF3

d) B₂F₆

e) SO₂

d) B₂F₆

100

Which of the following is a single replacement reaction?

a) CH₄_(g) + 2 O₂_(g) → CO₂_(g) + 2 H₂O_(l)

b) 2 KBr_(s) + Cl_2(g) → 2 Br_2(l) + 2 KCl_(s)

c) 2 KClO_3(s)→ 2 KCl_(s)+ 3 O₂_(g)

d) HCl(aq) + NaOH_(aq) → H₂O_(l) + NaCl_(aq)

e) Cu_(s)+ O_2(g) → Cu₂O_(s)

b) 2 KBr_(s) + Cl_2(g) → 2 Br_2(l)+ 2 KCl_(s)

100

Which of the following is incorrectly labeled?

a) CH₃OH, nonelectrolyte

b) HCN, weak electrolyte

c) HClO₃, strong electrolyte

d) CH₃COOH, weak electrolyte

e) NH₃, nonelectrolyte

100

Which one of the following statements is not correct?

a) Oxidation refers to a chemical reaction in which a substance loses electrons.

b) Reduction refers to a chemical reaction in which a substance gains electrons.

c) When a substance is oxidized, its oxidation number decreases.

d) An oxidizing agent is a substance that is reduced in a chemical reaction.

e) Statements A–D are all correct.

c) When a substance is oxidized, its oxidation number decreases.

100

Select the reacting ratio that is not applicable to the following reaction.

2 C₇H₁₆O_(l) + 21 O₂_(g)→ 14 CO_2(g) + 16 H₂O_(g)

a) 21 mol O₂ / 16 mol H₂O

b) 8 mol H₂O / 7 mol CO₂

c) 2 mol C₇H₁₆O / 21 mol O₂

d) 4 mol H₂O / 1 mol C₇H₁₆O

e) 3.5 mol CO₂ / 4 mol H₂O

d) 4 mol H₂O / 1 mol C₇H₁₆O

200

What is the percent by mass of hydrogen in ammonia, NH₃:Mm= 17.024 g/mol?

a) 5.92 %

b) 7.20 %

c) 17.8 %

d) 75.0 %

e) 21.6 %

c) 17.8 %

200

Select the coefficients that should be placed in front of each molecule, from left to right, to balance the following reaction:

__ H₃PO₄_(aq) + __ Ba(OH)_2(aq) → __ Ba₃(PO₄)_2(s)+ __H₂O_(l)

a) 2, 3, 1, 6

b) 2, 3, 1, 3

c) 2, 1, 1, 5

d) 4, 2, 2, 5

e) 1, 3, 1, 3

a) 2, 3, 1, 6

200

Determine which diagram below best represents the ionic compound Ca(IO₄)₂ dissolved in water. (show images)

200

What is the oxidation number of sulfur in SO₄^2-?

a) −2
b) +2
c) +4
d) +6
e) +8

^{(Not on Practice Exam)}

d) +6

200

If a reaction had a 72.64 % yield and a calculated theoretical yield of 24.47 g, what was the actual yield?

a) 56.43 g

b) 17.78 g

c) 13.86 g

d) 29.69 g

e) 23.74 g

b) 17.78 g

300

2. How many moles of ammonium cations are in 2.95 moles of ammonium phosphate, (NH₄)₃PO₄?

a) 2.95 mol

b) 0.983 mol

c) 44.1 mol

d) 35.4 mol

e) 8.85 mol

300

Predict which of the following reactants, when mixed together, will cause a reaction to occur.

a) Na₂SO_4(aq) + Zn(NO₃)_2(aq)→

b) K₂S_(aq) + Ni(ClO₄)_2(aq) →

c) NaOH_(aq) + BaSO_4(aq)→

d) MgCl_2(aq) + Fe(C₂H₃O₂)₃ →

e) AgClO_3(aq) + Pb(NO₃)₂ →

b) K₂S_(aq) + Ni(ClO₄)_2(aq) →

300

Which picture below best represents an atomic-level view of an aqueous HF solution? (Water molecules are left out) (show images)

300

Which substance is oxidized in the following oxidation-reduction reaction?

Zn_(s) + CuSO_4(aq) → ZnSO_4(a_q) + Cu_(s)

a) Zn
b) Cu
c) S
d) O
e) SO₄^2-

^{(Not on Practice Exam)}

a)Zn

300

If 1.00 mol HC₂H₃O₂was reacted with 1.00 mol Ba(OH)₂, what is the limiting reagent?

2 HC₂H₃O_2(aq) + Ba(OH)_2(aq) → 2 H₂O_(l) + Ba(C₂H₃O₂)_2(aq)

a) HC₂H₃O₂

b) Ba(OH)₂

c) H₂O

d) Ba(C₂H₃O₂)₂

e) HC₂H₃O₂ and Ba(OH)₂

a) HC₂H₃O₂

400

How many carbon atoms are in 3.00 moles of vitamin A, C₂₀H₃₀O?

a) 60.0 atoms

b) 3.61 x 1025 atoms

c) 23 atoms

d) 9.03 x 1022 atoms

e) 9.96 x 1023 atoms

b) 3.61 x 10²⁵ atoms

400

Give the total ionic and net ionic equations and determine spectator ions for the reaction between potassium chloride and lead (II) nitrate.

2K⁺_(aq)+ 2NO₃^-_{(aq) →}2K⁺_(aq)+ 2NO₃^-_(aq)

400

If 20.5 g of NaOH (Mm = 39.998) is added to 325.0 mL of water, what is the resulting concentration of the solution?

a) 1.58 M

b) 6.31 M

c) 0.513 M

d) 15.9 M

e) 6.66 M

a) 1.58 M

400

What is the reducing agent in the following oxidation-reduction reaction?

2Al_(s)+ 3CuCl_2(aq) → 2AlCl_3(aq) + 3Cu_(s)

a) Al
b) Cu
c) Cl
d) CuCl₂
e) AlCl₃

_{(Not on Practice Exam)}

a) Al

400

After the complete reaction of 0.750 mol HC₂H₃O₂ with 0.250 mol NaOH, how much excess reactant remains?

HC₂H₃O_2(aq) + NaOH_(aq) → H₂O_(l) + NaC₂H₃O_2(aq)

a) 0 mol

b) 0.250 mol

c) 0.500 mol

d) 0.750 mol

e) 0.300 mol

c) 0.500 mol

500

18. Determine the empirical formula for a compound that contains C, H, and O. It contains 54.53% C, 9.15% H, and 36.32% O by mass.

C₂H₄O

500

Which of the following is the correct net ionic equation for the reaction between aqueous silver nitrate and aqueous sodium chloride?

a) AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq)
b) Ag⁺(aq) + Cl^-(aq) → AgCl(s)
c) Na⁺(aq) + NO₃^-(aq) → NaNO₃(aq)
d) Ag⁺(aq) + NO₃^-(aq) → AgNO₃(aq)
e) Na⁺(aq) + Cl⁻(aq) → NaCl(aq)

_{(Not on Practice Exam)}

b) Ag⁺(aq) + Cl^-(aq) → AgCl(s)

500

Determine the final concentration of KCl after 1.75 L of 0.750 M KCl is diluted by the addition of 1.50 L of water.

0.404M KCl

500

What is the oxidizing agent in the following oxidation-reduction reaction?

2MnO_2(s) + KClO_3(aq) + 2KOH_(aq) → 2KMnO_4(aq) + KCl_(aq) + H₂O_(l)

a) Cl in KClO₃

b) Mn in MnO₂

c) K in KClO₃

d) O in KClO₃

e) O in MnO₂

a) Cl in KClO3

500

What volume of 0.350 M KCl is required to react exactly with 50.0 mL of 0.250 M Pb(NO₃)₂solution?

71.4mL