Chemistry Spring Final exam review

Multiple Choice

Which of the following best describes a homogeneous mixture?

• A mixture where you can see the different layers

• A mixture of two or more substances not chemically combined and uniform throughout

• A single pure substance

• A mixture that separates into layers over time

Open Ended

Why is it important to understand the concept of homogeneous mixtures in chemistry?

Multiple Choice

Which of the following best describes the role of a solvent in a solution?

• The substance that is dissolved

• The substance that does the dissolving

• A solid that forms in a solution

• A gas that escapes from a solution

Open Ended

Explain how temperature and pressure affect the solubility of a solute in a solvent.

Multiple Select

Which of the following actions will increase the rate at which a solute dissolves in a solvent?

• Decreasing temperature

• Stirring

• Powdering the solute

• Increasing pressure

Fill in the Blanks

A polar molecule is one in which the positive and negative charges are

.

Open Ended

What is the formula for calculating molarity?

Fill in the Blanks

You have 25 grams of NaCl. To convert this to moles, you should

by the molar mass.

Fill in the Blanks

2.3 mol of NaCl in 0.45L of solution, calculate molarity.

Multiple Choice

Which of the following statements correctly describes the difference between Arrhenius acids and bases?

• Arrhenius acids release hydrogen ions (H+) in water, while Arrhenius bases release hydroxide ions (OH-) in water.

• Arrhenius acids release hydroxide ions (OH-) in water, while Arrhenius bases release hydrogen ions (H+) in water.

• Arrhenius acids are always sour, while Arrhenius bases are always slippery.

• Arrhenius acids turn litmus paper blue, while Arrhenius bases turn it red.

Multiple Choice

Based on the Bronsted-Lowry definition, what is the difference between acids and bases?

• Acids are proton donors, bases are proton acceptors.

• Acids are proton acceptors, bases are proton donors.

• Acids release hydroxide ions, bases release hydrogen ions.

• Acids are always sour, bases are always bitter.

Multiple Choice

Which of the following statements about endothermic and exothermic reactions is correct?

• Endothermic reactions absorb heat, exothermic reactions release heat.

• Endothermic reactions release heat, exothermic reactions absorb heat.

• Both endothermic and exothermic reactions absorb heat.

• Both endothermic and exothermic reactions release heat.

Fill in the Blanks

The symbol for enthalpy is

.

Open Ended

Explain how you can determine if a chemical reaction is exothermic or endothermic based on the position of ΔH in the chemical equation.

Multiple Choice

Compare the energy changes in exothermic and endothermic reactions as shown in the graphs. What is the main difference between the two types of reactions?

• Exothermic reactions release energy while endothermic reactions absorb energy.

• Exothermic reactions absorb energy while endothermic reactions release energy.

• Both reactions release energy.

• Both reactions absorb energy.

Fill in the Blanks

The minimum amount of energy that must be added to a mixture of reactants for a chemical reaction to occur is called

.

Open Ended

Explain the significance of activation energy in a chemical reaction and how it is represented on a reaction pathway graph.

Multiple Choice

A homogeneous mixture is best described as:

• A mixture where you can see the different layers

• Two or more substances not chemically combined and uniform throughout

• A single pure substance

• A mixture that is chemically combined

Open Ended

How would you explain the difference between a homogeneous mixture and a heterogeneous mixture, based on what you learned today?