Chapter 2 Measurements and Calculations

A student performed 4 trials to measure the volume of

an unknown liquid. Is the following set of data accurate, precise, both or neither if the actual value is 23.4 mL?

Data: 20.4mL 20.3mL 20.1mL 20.5mL

• a. Accurate

• b. Precise

• c. Accurate and precise

• d. Neither accurate or precise

Indicate the number of significant figures in the

number 70400

• a. 2

• b. 3

• c. 4

• d. 5

Indicate the number of sig figs in the number 700

• a. 3

• b. 2

• c. 1

• d. 4

Indicate the number of sig figs in the number 15.60

• a. 1

• b. 2

• c. 3

• d. 4

Indicate the number of sig figs in the number 0.00230

• a. 6

• b. 2

• c. 5

• d. 3

Indicate the number of sig figs in the number 72300.

• a. 5

• b. 3

• c. 2

• d.4

Solve the following expression using the correct

number of significant figures and units

24.4mL + 110mL + 145.30mL – 12.8mL

• a. 292.5mL

• b. 266.90mL

• c. 270mL

• d. 290mL

• e. 267mL

Solve the following expression: 9.8g ÷ 0.123mL

• a. 79.674g/L

• b. 79.6g/L

• c. 80.0g/L

• d. 8.0 x 10¹ g/L

• e. 80g/L

A student in chemistry measures the mass of a solid with an accepted mass of 200.00 grams on the balance assigned to him in the lab. He records the mass of this object as 196.5 g. Calculate his percent error.

• a. 17.5%

• b. 1.75%

• c. 1.8%

• d. 1.80%

• e. 18.0%

The number 6.33 x 10² is the same as

• a. 6.33

• b. 633

• c. 0.633

• d. 0.0633