Q: A student heats 10.0 g of water from 25.0 °C to 35.0 °C. Given the specific heat capacity of water is $$4.184 \text{ J/g} \cdot \text{°C}$$, how much heat is absorbed?

$$q = 10.0 \times 4.184 \times (35.0 - 25.0) = 418.4 \text{ J}$$

Q: A candy bar contains 225 Cal of nutritional energy. How many joules does it contain? ($$1 \text{ Cal} = 1000 \text{ cal}$$, $$1 \text{ cal} = 4.184 \text{ J})$$

$$225 \times 1000 \times 4.184 = 941,400 \text{ J}$$

Q: Which of the following is the correct formula for calculating heat absorbed or released by a substance?

$$q = m \times C \times \Delta T$$

Question 1

Which of the following statements best describes a compound?

Accepted Answer

A pure substance composed of two or more elements in fixed, definite proportions.

Question 2

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

Accepted Answer

Water boiling to form steam.

Question 3

A sample contains both sand and salt. Which classification best describes this sample?

Accepted Answer

Heterogeneous mixture

Question 4

Which property is a chemical property?

Accepted Answer

Flammability

Question 5

Which statement about the law of conservation of mass is correct?

Accepted Answer

The total mass of reactants equals the total mass of products in a chemical reaction.

Question 6

Which of the following is true about gases?

Accepted Answer

Gases assume the shape and volume of their container.

Question 7

A student heats 10.0 g of water from 25.0 °C to 35.0 °C. Given the specific heat capacity of water is $$4.184 	ext{ J/g} \cdot 	ext{°C}$$, how much heat is absorbed?

Accepted Answer

$$q = 10.0 	imes 4.184 	imes (35.0 - 25.0) = 418.4 	ext{ J}$$

Question 8

Which of the following best describes an amorphous solid?

Accepted Answer

Atoms or molecules are not arranged in any long-range order.

Question 9

Which equation correctly converts Celsius to Kelvin?

Accepted Answer

$$K = ^\circ C + 273.15$$

Question 10

A chemical reaction absorbs energy from its surroundings. What type of reaction is this?

Accepted Answer

Endothermic

Question 11

Which of the following is NOT a unit of energy?

Accepted Answer

Degree Celsius (°C)

Question 12

Which statement about temperature and heat is correct?

Accepted Answer

Heat is the transfer of thermal energy due to a temperature difference.

Question 13

A candy bar contains 225 Cal of nutritional energy. How many joules does it contain? ($$1 	ext{ Cal} = 1000 	ext{ cal}$$, $$1 	ext{ cal} = 4.184 	ext{ J})$$

Accepted Answer

$$225 	imes 1000 	imes 4.184 = 941,400 	ext{ J}$$

Question 14

Which of the following is a homogeneous mixture?

Accepted Answer

Sweetened tea

Question 15

Which of the following is a physical property?

Accepted Answer

Boiling point

Question 16

Which of the following best describes the molecular motion in a liquid?

Accepted Answer

Atoms or molecules are free to move relative to one another.

Question 17

A sample of butane is vaporized in a lighter. What type of change is this?

Accepted Answer

Physical change

Question 18

Which of the following statements about exothermic reactions is correct?

Accepted Answer

Exothermic reactions release energy to the surroundings.

Question 19

Which of the following is the correct formula for calculating heat absorbed or released by a substance?

Accepted Answer

$$q = m 	imes C 	imes \Delta T$$

Question 20

Which of the following best describes the difference between a physical and a chemical change?

Accepted Answer

Chemical changes alter the composition of matter, while physical changes do not.

Chapter 3: Matter and Energy – Structured Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard