Q: A student measures the mass of a rock as 12.45 g and its volume as 2.50 mL. What is the density of the rock, and how many significant figures should the answer have?

$$4.98 \\ \text{g/mL}$$, 3 significant figures

Q: A sample of metal has a mass of 45.0 g and a volume of 15.0 mL. Will it float or sink in water? (Density of water = $$1.00 \\ \text{g/mL})$$

It will sink, because its density is $$3.00 \\ \text{g/mL}.$$

Question 1

Which of the following best describes a homogeneous mixture?

Accepted Answer

A sample of air in a room, where the composition is uniform throughout.

Question 2

Which of the following is a physical change?

Accepted Answer

Melting of ice to form liquid water.

Question 3

A student measures the mass of a rock as 12.45 g and its volume as 2.50 mL. What is the density of the rock, and how many significant figures should the answer have?

Accepted Answer

$$4.98 \ 	ext{g/mL}$$, 3 significant figures

Question 4

Which of the following is an example of a compound?

Accepted Answer

Table salt ($$	ext{NaCl})$$

Question 5

Convert a temperature of $$25 \ ^\circ 	ext{C} to $$Kelvin.

Accepted Answer

$$298 \ 	ext{K}$$

Question 6

Which of the following statements about density is correct?

Accepted Answer

An object will float in water if its density is less than $$1.00 \ 	ext{g/mL}.$$

Question 7

A nutrition label states that a serving of food contains 200 Calories. How many joules is this equivalent to? (1 Calorie = 4.184 kJ)

Accepted Answer

$$836,800 \ 	ext{J}$$

Question 8

Which of the following best describes potential energy?

Accepted Answer

Energy stored in a stretched rubber band.

Question 9

Which of the following is an exact number and does NOT affect significant figures in calculations?

Accepted Answer

1 inch = 2.54 cm

Question 10

A student needs to convert 3.00 quarts to liters. Given that $$1 \text{qt} = 0.946 \text{L}$$, what is the correct answer with the proper number of significant figures?

Accepted Answer

$$2.84 \ 	ext{L}$$

Question 11

Which of the following is a heterogeneous mixture?

Accepted Answer

A salad with lettuce, tomatoes, and cucumbers.

Question 12

Which of the following is a chemical property?

Accepted Answer

The ability of iron to rust when exposed to air.

Question 13

A patient’s body temperature is measured as $$102.2 \ ^\circ 	ext{F}. $$What is this temperature in Celsius? (Use $$^\circ 	ext{C} = ( ^\circ 	ext{F} - 32 ) 	imes \frac{5}{9})$$

Accepted Answer

$$39.0 \ ^\circ 	ext{C}$$

Question 14

Which of the following best describes kinetic energy?

Accepted Answer

A moving car traveling down the highway.

Question 15

Which of the following is the correct definition of specific gravity?

Accepted Answer

The density of a substance divided by the density of water.

Question 16

A sample of metal has a mass of 45.0 g and a volume of 15.0 mL. Will it float or sink in water? (Density of water = $$1.00 \ 	ext{g/mL})$$

Accepted Answer

It will sink, because its density is $$3.00 \ 	ext{g/mL}.$$

Question 17

Which of the following is a correct statement about the metric system?

Accepted Answer

A kilometer is $$10^3$$ meters.

Question 18

Which of the following is a correct conversion factor for U.S. to metric units?

Accepted Answer

$$1 \text{in} = 2.54 \text{cm}$$

Question 19

A solution is prepared by dissolving 5.00 g of salt in 95.0 g of water. Which of the following best describes the resulting mixture?

Accepted Answer

A homogeneous mixture

Question 20

Which of the following is a correct statement about significant figures?

Accepted Answer

When multiplying or dividing, the answer should have the same number of significant figures as the measurement with the fewest significant figures.

Test 1: CHE 140 Study Guide: Matter, Temperature, Energy, Units, Density, and Conversions

Guida di studio - Domande di pratica

Study guide - Flashcard