Chem Unit 1

Q2. Aluminum metal has a density of 2.70 g/mL. If you have a sample that occupies 10.5 mL, what is its mass?

• 28.3 g

• 3.89 g

• 0.257 g

• 7.80 g

Q3. Copper has a density of 8.96 g/cm³. If a cylinder of copper weighing 34.94 grams is dropped into a graduated cylinder containing 20.00 mL of water, what will be the new water level?

• 3.905 mL

• 0.2560 mL

• 16.10 mL

• 23.90 mL

Q4. A student measures a sample on a lab scale to be 62.5 g, but after realizing the scale was not properly balanced the actual mass of the sample was 57.8 g. What is the percent error?

• 7.52%

• -7.52%

• 8.13%

• 4.7%

Q5. The boiling point of a chemical (Ethanol) is 78.40 degrees Celsius. A student conducts an experiment and finds the boiling point of Ethanol to be 75.0 degrees Celsius. What is the percent error of the student's measurement?

• 4.34%

• 4.53%

• 3.40%

Q6. Which of the following choices best represents the length reading from the metric ruler pictured?

• 8.5 cm

• 8.450 cm

• 8.45 cm

• 8 cm

Q7. Which piece of lab equipment would you use to accurately measure out 12.5 mL of liquid? (Lab Equipment)

• Graduated cylinder

• Beaker

• Erlenmeyer Flask

• Test Tube

Q8. Round the following measurement to 2 significant figures: 0.00354 cm

• 35 cm

• 0.0035 cm

• 0.00350 cm

• 0.003 cm

Q9. Round the following number to 4 significant figures: 17.995

• 18.00

• 17.99

• 18

• 17.00

Q10a. Perform the following operation below with a calculator and answer using the correct significant figures 37.76 + 3.907 + 226.4 =

• 268.067

• 268.07

• 268.1

• 268.0