Concentration and Molarity Practice Test

Review the following concepts if needed:

• Concentration and Molarity Help
• Conversion of Mass to Moles Help

Concentration and Molarity Practice Test

1. Concentration

(a) is important to understand chemistry

(b) is the volume per velocity of molecular movement

(c) can mean the difference between life and death

(d) is found by mixing a weak acid and strong base

2. Percent mass of solution

(a) is used to find the amount of solute in solvent

(b) is used to weigh grams onto a scientific balance

(c) never uses the total mass of the solute

(d) can be achieved without knowing the atomic weight of the chemicals involved

3. Chemical concentrations are most often expressed as

(a) ppc (parts per centimeter)

(b) ppb (parts per billion)

(c) pgs (parts per gram solvent)

(d) ppm (parts per million) 

4. Molarity

(a) equals mass

(b) is used to find general amounts

(c) equals concentration

(d) has the opposite function of polarity

5. A mole

(a) has 10 ² atoms in a sample

(b) has the same number of atoms in a sample as 12 grams of ¹² C

(c) is a small, black, furry rodent that lives underground

(d) is seldom used in modern chemical calculations

6. Avogadro’s number

(a) is equal to 6.02 × 10 ²³ atoms or molecules

(b) is equal to 4.20 × 10 ²³ atoms or molecules

(c) is equal to 2.60 × 10 ²³ atoms or molecules

(d) is equal to 23.02 × 10 ⁶ atoms or molecules

7. Avogadro’s number

(a) was first suggested by Anatasia Avogadro

(b) has never been proven decisively

(c) is used to calculate the number of electrons in a sample

(d) is equal to one mole

8. Empirical formulas

(a) show the elements’ proportions in a compound

(b) indicate probable ideal gas combinations

(c) are always the same as the molecular formula

(d) give the whole number ratio of elements in a compound

9. Molar mass (MM) is measured in

(a) moles/solute

(b) grams/liter

(c) grams/mole

(d) moles/solvent

10. In order to convert mass to moles, you need

(a) a calculator

(b) a list of atomic masses

(c) the boiling point of the solvent

(d) a very sensitive scale

Answers

1. C

2. A

3. D

4. C

5. B

6. A

7. D

8. D

9. C

10. B