AP Chem Final Exam

__ Fe(OH)₂ (s) + __ H₃PO₄ (aq) → __ Fe₃ (PO₄)₂ (s) + __ H₂O(l)

After the above chemical equation is balanced, the lowest whole-number coefficient for water is:

• 3

• 1

• 9

• 6

Which of the following best represents the balanced net ionic equation for the reaction of lead(II) carbonate with concentrated hydrochloric acid? In this reaction, all lead compounds are insoluble.

• Pb₂CO₃ + 2H⁺ + Cl⁻ → Pb₂Cl + CO₂ + H₂O

• PbCO₃ + 2H⁺ + 2Cl⁻ → PbCl₂ + CO₂ + H₂O

• PbCO₃ + 2H+ → Pb₂⁺ + CO₂ + H₂O

• PbCO₃ + 2Cl⁻ → PbCl₂ + CO₃ ²⁻

When 50.0 mL of 1.0 M AgNO₃ is added to 50.0 mL of 0.50 M HCl, a precipitate of AgCl forms. After the reaction is complete, what is the concentration of silver ions in the solution?

• 0.50 M

• 0.0 M

• 1.0 M

• 0.25 M

For which of the following substances is the formula mass the same for both the empirical and molecular formulas?

• H₂C₂O₄

• C₆H₁₂O₆

• CO₂

• H₂O₂

2CH₄ (g) + O₂ (g) <--> 2CO(g) + 4H₂ (g) ... ΔH < 0

To increase the value of the equilibrium constant, K, in the above equation, which of the following changes must be made?

• increase the temperature

• increase the volume

• decrease the temperature

• add CO(g)

2NO₂ (g)   ↔  2NO(g) + O₂ (g)

The above materials were sealed in a flask and allowed to come to equilibrium at a certain temperature. A small quantity of O2 (g) was added to the flask, and the mixture was allowed to return to equilibrium at the same temperature. Which of the following has increased over its original equilibrium value?

• the quantity of NO2 (g) present

• the quantity of NO(g) present

• the equilibrium constant, K, increases

• the rate of the reaction

Which of the following best represents the balanced net ionic equation for the reaction of silver carbonate with concentrated hydrochloric acid? Silver ions have a 1+ charge. In this reaction, all silver compounds are insoluble

• 2AgCO₃ + 4H⁺ + Cl⁻ → Ag₂Cl + 2CO₂ + 2H₂O

• Ag₂CO₃ + 2H⁺ + 2Cl⁻ → 2AgCl + CO₂ + H₂O

• AgCO₃ + 2H⁺ → Ag⁺ + CO₂ + H₂O

• AgCO₃ + 2H⁺ → Ag⁺ + CO₂ + H₂O

Sodium sulfate forms several hydrates. A sample of a hydrate is heated until all the water is removed. What is the formula of the original hydrate if it loses 43% of its mass when heated?

• Na₂SO₄  ●  H₂O

• Na₂SO₄  ●  2H₂O

• Na₂SO₄  ●  6H₂O

• Na₂SO₄  ●  8H₂O

A sample of argon gas is sealed in a container. The volume of the container is doubled. If the pressure remains constant, what happens to the absolute temperature?

• The temperature does not change.

• The temperature is halved.

• The temperature is doubled.

• The temperature is squared.

Each of four 10.0 L containers is filled with a different noble gas (He, Ne, Ar, and Kr). Each container contains 0.5 mole of gas at 298 K. Assuming all four gases are behaving ideally, which of the following is the same for all four samples?

• average speed of the atoms

• density of the gas in the container

• All properties are the same for gases behaving ideally

• average kinetic energy of the atoms