EAS Chemistry Spring 2023 Final Exam Review

What is the pOH of a substance that has a pH of 9?

Hint: pH + pOH = 14

• 7

• 4

• 1

• 5

Answer explanation

pH + pOH = 14

pOH = 14 - pH

pOH = 14 - 9 = 5

Which of the following is a property of a base?

• Sour taste

• pH above 7

• Forms H⁺ ions

• Feels sticky

Answer explanation

Bases have a bitter taste, feel slippery, form OH^- ions upon dissociation, and have a pH above 7.

The substance that gets dissolved when forming a solution is the __________.

• solute

• solvent

Answer explanation

Solute - the substance in a solution that gets dissolved (usually in smaller quantity).

Example: Salt, sugar, etc.

Solvent - the substance in a solution that does the dissolving (usually in larger quantity).

Example: Water

A strong acid ________ dissociate/ionize completely.

• will not

• will

Answer explanation

Strong acids completely dissociate in solution; therefore, they have a high [H⁺] and a low pH (0-3).

Weak acids partially dissociate in solution; therefore, they have a lower [H⁺] and a higher pH (3-6.9).

Which of the following is NOT a property of acids?

• Feels sticky

• pH below 7

• Bitter taste

• Form H⁺ ions

Answer explanation

Acids have a sour taste, feel sticky, form H⁺ ions upon dissociation, and a pH below 7.

Which type of solution contains more dissolved solute than it could under normal conditions?

• Saturated solution

• Supersaturated solution

• Unsaturated solution

Answer explanation

Unsaturated solution - capable of dissolving more solute.

Saturated solution - contains the maximum amount of solute.

Supersatured solution - contains more solute than it could under normal conditions.

How many liters are in 3.55 moles of H₂?

• 22.4 L

• 0.16 L

• 6.31 L

• 79.52 L

Answer explanation

1 mole of any gas (at STP) occupies 22.4 L of volume.

To better dissolve a gas into solution, you must __________.

Hint: There are two correct answers

• increase pressure

• heat the solution

• cool the solution

• decrease pressure

Answer explanation

When the solute in a solution is a gas, you must increase the pressure and decrease the temperature.

Decreasing the temperature causes the KE of the gas molecules to decrease; thus, the gas particles will "slow down" and stay in solution.

Increasing the pressure "forces" the gas particles to stay in solution.

• 30.89 g H₂O

• 0.10 g H₂O

• 7.72 g H₂O

• 15.45 g H₂O

Answer explanation

How many atoms are in 1.00 mole of Aluminum (Al)?

• 22.4 atoms

• 1.00 atoms

• 26.98 atoms

• 6.02 x 10²³ atoms

Answer explanation

Avogadro's Number:

1 mole of any substance contains 6.02 x 10²³ atoms, molecules, or particles.