Q: A student heats 100 g of water from 20°C to 80°C. How much energy (in joules) is required? ($$1\ \mathrm{cal} = 4.184\ \mathrm{J}$$, $$1\ \mathrm{cal}$$ heats $$1\ \mathrm{g}$$ water by $$1^{\circ}$$\mathrm{C}$$)

$$Q = 100\ \mathrm{g} \times 60$$^{\circ}$$\mathrm{C} \times 4.184\ \mathrm{J} = 25,104\ \mathrm{J}$$

Q: Which of the following is a correct definition of density?

$$d = \frac{\text{mass}}{\text{volume}}$$

Question 1

Which of the following is an example of a chemical change?

Accepted Answer

Copper tarnishing when exposed to air

Question 2

A student mixes sand and salt in a beaker. Which type of mixture is formed?

Accepted Answer

Heterogeneous mixture

Question 3

Which statement best describes the particles in a liquid?

Accepted Answer

They are close together but mobile.

Question 4

Which of the following is a physical property?

Accepted Answer

Color

Question 5

A sample of metal has a mass of 45.0 g and a volume of 15.0 mL. What is its density?

Accepted Answer

$$d = \frac{45.0\ \mathrm{g}}{15.0\ \mathrm{mL}} = 3.0\ \mathrm{g/mL}$$

Question 6

Which of the following is NOT a characteristic of a solid?

Accepted Answer

Particles move very fast

Question 7

Which of the following best describes a homogeneous mixture?

Accepted Answer

The composition is uniform throughout.

Question 8

Which of the following is a chemical property?

Accepted Answer

Ability to react with oxygen

Question 9

A student heats 100 g of water from 20°C to 80°C. How much energy (in joules) is required? ($$1\ \mathrm{cal} = 4.184\ \mathrm{J}$$, $$1\ \mathrm{cal}$$ heats $$1\ \mathrm{g}$$ water by $$1^{\circ}$$\mathrm{C}$$)

Accepted Answer

$$Q = 100\ \mathrm{g} 	imes 60$$^{\circ}$$\mathrm{C} 	imes 4.184\ \mathrm{J} = 25,104\ \mathrm{J}$$

Question 10

Which of the following statements about energy is correct?

Accepted Answer

Kinetic energy is energy due to motion.

Question 11

Which of the following is a correct conversion between Celsius and Kelvin?

Accepted Answer

$$K = ^{\circ}\mathrm{C} + 273.15$$

Question 12

Which of the following is NOT a mixture?

Accepted Answer

Water

Question 13

A student finds a liquid that takes the shape of its container but has a definite volume. What state of matter is this?

Accepted Answer

Liquid

Question 14

Which of the following is an example of kinetic energy?

Accepted Answer

A moving car

Question 15

Which of the following is a correct definition of density?

Accepted Answer

$$d = \frac{	ext{mass}}{	ext{volume}}$$

Question 16

Which of the following is a heterogeneous mixture?

Accepted Answer

Hot fudge sundae

Question 17

Which of the following is a physical change?

Accepted Answer

Copper being drawn into wires

Question 18

Which of the following statements about temperature and heat is correct?

Accepted Answer

Heat is the energy transferred due to a temperature difference.

Question 19

A block of ice melts into water. Which type of change is this?

Accepted Answer

Physical change

Question 20

Which of the following is a compound?

Accepted Answer

Water

Introduction to Chemistry: Matter, Properties, and Energy

Guida di studio - Domande di pratica

Study guide - Flashcard