AP Chemistry Practice Test 2021 (30 Sample Question Answers)

In most of its compounds, this element exists as a monatomic cation

Which of the following groups has the species correctly listed in order of decreasing radius?

Which of the following elements has the lowest electronegativity?

Which of the following represents the correct formula for hexaamminecobalt (III) nitrate?

The discovery that atoms have small, dense nuclei is credited to which of the following?

Choose the strongest Lewis acid from the following 

CH₄

. _____Mn(OH)₂ (s) + ____H₃AsO₄ ( aq )→_____ Mn ₃(AsO₄) ₂(s) +_____ H₂O(1)

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

A student mixes 50.0 mL of 0.10 M Fe(NO₃)₂ solution with 50.0 mL of 0.10 M KOH. A green precipitate forms, and the concentration of the hydroxide ion becomes very small. Which of the following correctly places the concentrations of the remaining ions in order of decreasing concentration?

14 H⁺ + 6 Fe²⁺ + Cr₂O₇ ^2- → 2 Cr³⁺ + 6 Fe³⁺ +7 H₂O

The above reaction is used in the titration of an iron solution. What is the concentration of the iron solution if it takes 45.20 mL of 0.1000 M Cr₂O₇ ^2- solution to titrate 75.00 mL of an acidified iron solution?

Manganese, Mn, forms a number of oxides. A particular oxide is 49.5% mass Mn. What is the simplest formula for this oxide?

2 KMnO₄ + 5 H₂C₂O₄ + 3 H₂SO₄ → K₂SO₄ + 2 MnSO₄ + 10 CO₂ + 8 H₂O

How many moles of MnSO₄ are produced when 2.0 mol of KMnO₄, 2.5 mol of H2C2O4, and 3.0 mol of H₂SO₄ are mixed?

Ba + 2 H₂O → Ba(OH)₂ + H₂

Barium reacts with water according to the above reaction. What volume of hydrogen gas, at standard temperature and pressure, is produced from 0.400 mol of barium?

A sample of chlorine gas is placed in a container at constant pressure. The sample is heated until the absolute temperature is doubled. This will also double which of the following?

A balloon contains 2.0 g of hydrogen gas. A second balloon contains 4.0 g of helium gas. Both balloons are at the same temperature and pressure. Pick the false statement from the following list.

The volume and pressure of a real gas are not the same as those calculated from the ideal gas equation, because the ideal gas equation does NOT take into account:

Aluminum metal reacts with HCl to produce aluminum chloride and hydrogen gas. What volume of hydrogen gas, at STP, is produced when 13.5 g of aluminum is mixed with an excess of HCl?

A sample containing the gases carbon dioxide, carbon monoxide, and water vapor was analyzed and found to contain 4.5 mol of carbon dioxide, 4.0 mol of carbon monoxide, and 1.5 mol of water vapor. The mixture had a total pressure of 1.2 atm. What was the partial pressure of the carbon monoxide?

An ideal gas sample weighing 0.548 g at 100°C and 0.993 atm has a volume of 0.237 L. Determine the molar mass of the gas.

If a sample of He effuses at a rate of 30 mol per hour at 45°C, which of the gases below will effuse at approximately one-half the rate under the same conditions?

CO

The energy required to produce a gaseous cation from a gaseous atom in the ground state

The energy required to completely separate the ions from a solid is

Oxidation of ClF by F₂ yields ClF₃, an important fluorinating agent formerly used to produce the uranium compounds in nuclear fuels: ClF(g) + F₂(g) → ClF₃(l). Use the following thermochemical equations to calculate ΔH°_rxn for the production of ClF_3:

1. 2 ClF(g) + O₂(g) → Cl₂O(g) + OF₂(g)
ΔH° = 167.5 kJ

2. 2 F₂(g) + O₂(g) kJ→ 2 OF₂(g)
ΔH°=−43.5

3. 2 ClF₃(l) + 2 O₂(g) → Cl₂O(g) + 3 OF₂(g)
ΔH° = 394.1 kJ

Choose the reaction expected to have the greatest increase in entropy.

A certain reaction is nonspontaneous under standard conditions, but becomes spontaneous at lower temperatures. What conclusions may be drawn under standard conditions?

Which of the following groups contains only atoms that are paramagnetic in their ground state?

VSEPR predicts that an IF5 molecule will be which of the following shapes?

Magnesium reacts with element X to form an ionic compound. If the ground-state electron configuration of X is 1s² 2s²
2p³ , what is the simplest formula for this compound?

Which of the following does not have one or more π bonds?

Which of the following is nonpolar?

The only substance listed below that contains ionic, σ, and π bonds is: