Q: Which of the following is the correct equation for density?

$$\text{Density} = \frac{\text{Mass}}{\text{Volume}}$$

Q: Convert $$3.5 \ \mathrm{km^2$} to$$ $$\mathrm{m^2$}. (1 km = 1000 m)$$

$$3.5 \times 10^6$ \ \mathrm{m^2$}$$

Question 1

Which of the following numbers is correctly expressed in scientific notation?

Accepted Answer

$$3.32 	imes 10^8$

Question 2

A laboratory thermometer shows a temperature between 38.0°C and 39.0°C. If you estimate the last digit, which of the following is an appropriate way to record the temperature?

Accepted Answer

38.7°C

Question 3

How many significant figures are in the measurement 0.00250 g?

Accepted Answer

3

Question 4

Which of the following numbers is ambiguous in terms of significant figures?

Accepted Answer

5400

Question 5

Perform the following calculation and report the answer to the correct number of significant figures: $$4.2 	imes 3.56$$

Accepted Answer

$$15$$

Question 6

A runner completes 10.0 km on a track that is 255 m per lap. How many laps does the runner complete? (Report to the correct number of significant figures.)

Accepted Answer

39.2 laps

Question 7

A prescription requires 11.5 mg/kg of body weight. What is the dose in g for a 145-lb patient? (1 kg = 2.205 lb)

Accepted Answer

0.756 g

Question 8

Convert 56.0 cm to inches. (1 inch = 2.54 cm, exact)

Accepted Answer

22.0 inches

Question 9

A jeweler claims a ring is platinum. Its mass is 5.84 g and it displaces 0.543 mL of water. The density of platinum is $$21.4 \ \mathrm{g/mL}. Is $$the ring platinum?

Accepted Answer

No, because the calculated density is much less than $$21.4 \ \mathrm{g/mL}$$

Question 10

A chemist needs a 23.5-kg sample of ethanol (density $$0.789 \ \mathrm{g/mL}). $$What volume in liters should be used?

Accepted Answer

29.8 L

Question 11

Which of the following is the correct equation for density?

Accepted Answer

$$	ext{Density} = \frac{	ext{Mass}}{	ext{Volume}}$$

Question 12

A steel cylinder has a volume of $$0.350 \ \mathrm{L}$$ and a density of $$7.85 \ \mathrm{g/cm^3$}. $$What is its mass in kilograms?

Accepted Answer

2.75 kg

Question 13

Convert $$3.5 \ \mathrm{km^2$} to$$ $$\mathrm{m^2$}. (1 km = 1000 m)$$

Accepted Answer

$$3.5 	imes 10^6$ \ \mathrm{m^2$}$$

Question 14

A drop of acetone has a mass of 35 mg and a density of $$0.791 \ \mathrm{g/cm^3$}. $$What is its volume in cubic centimeters?

Accepted Answer

0.0443 cm$$^3$$

Question 15

Which of the following best describes why conversion factors based on definitions (such as 1 inch = 2.54 cm) do not limit the number of significant figures in a calculation?

Accepted Answer

They are considered exact and have an unlimited number of significant figures.

Question 16

A gold-colored pebble has a mass of 23.2 mg and a volume of $$1.20 \ \mathrm{mm^3$}. $$What is its density in $$\mathrm{g/cm^3$}$$?

Accepted Answer

19.3 $$\mathrm{g/cm^3$}$$

Measurement and Problem Solving – Introductory Chemistry Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard