Q: Which of the following equations is used to calculate the heat required to change the temperature of a substance?

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

Question 1

Which of the following best describes a homogeneous mixture, and which is a real-world example?

Accepted Answer

A mixture with a uniform composition throughout; brass (copper and zinc)

Question 2

A sample of matter is shiny, conducts electricity, and is composed of only one type of atom. Which classification best fits this sample?

Accepted Answer

Element

Question 3

Which of the following is a chemical change?

Accepted Answer

Iron rusting in an old car

Question 4

A 50.0 g sample of steam at $$100\ ^\circ\mathrm{C}$$ condenses to liquid water at $$100\ ^\circ\mathrm{C}. $$How much energy is released? (Heat of vaporization of water = $$2260\ \mathrm{J/g})$$

Accepted Answer

$$113\ \mathrm{kJ}$$

Question 5

Which equation correctly converts a temperature from Celsius to Kelvin?

Accepted Answer

$$K = ^\circ\!C + 273$$

Question 6

A cup of whole milk contains 12 g of carbohydrate, 9 g of fat, and 9 g of protein. Using the energy values $$4\ \mathrm{kcal/g}$$ for carbohydrate, $$9\ \mathrm{kcal/g}$$ for fat, and $$4\ \mathrm{kcal/g}$$ for protein, how many kilocalories does the milk contain (rounded to the tens place)?

Accepted Answer

150 kcal

Question 7

Which of the following statements about specific heat is correct?

Accepted Answer

Water has a higher specific heat than sand, so it heats and cools more slowly.

Question 8

Which process is an example of sublimation?

Accepted Answer

Dry ice changing directly from solid to gas

Question 9

A 24.8 g sample of metal absorbs 275 J of energy, causing its temperature to rise from $$21.5\ ^\circ\mathrm{C} to$$ $$48.1\ ^\circ\mathrm{C}. $$What is the specific heat of the metal? Use $$q = m 	imes c 	imes \Delta T.$$

Accepted Answer

$$0.40\ \mathrm{J/g\ ^\circ C}$$

Question 10

Which of the following is a physical property?

Accepted Answer

Copper is a shiny metal.

Question 11

A patient with hypothermia has a body temperature of $$34.0\ ^\circ\mathrm{C}. $$What is this temperature in Kelvin?

Accepted Answer

$$307\ \mathrm{K}$$

Question 12

Which of the following best describes the energy transformation in a hydroelectric dam?

Accepted Answer

Potential energy of water is converted to kinetic energy as water flows over the dam.

Question 13

How many calories are equivalent to 150 J of energy? ($$1\ \mathrm{cal} = 4.184\ \mathrm{J})$$

Accepted Answer

$$36\ \mathrm{cal}$$

Question 14

Which of the following is NOT a characteristic of gases?

Accepted Answer

Particles are close together and move slowly.

Question 15

Which of the following best describes what happens during condensation?

Accepted Answer

Gas particles lose kinetic energy and become a liquid.

Question 16

Which of the following is a heterogeneous mixture?

Accepted Answer

A mixture of water and copper metal

Question 17

Which of the following equations is used to calculate the heat required to change the temperature of a substance?

Accepted Answer

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

Question 18

A plateau (horizontal line) on a heating curve represents:

Accepted Answer

A change of state at constant temperature

Question 19

Which of the following is an example of potential energy in the human body?

Accepted Answer

The energy stored in a peanut butter and jelly sandwich

Question 20

How much heat (in kJ) is required to melt 32.0 g of ice at $$0\ ^\circ\mathrm{C}$$? (Heat of fusion for water = $$334\ \mathrm{J/g})$$

Accepted Answer

$$10.7\ \mathrm{kJ}$$

Chapter 3: Matter and Energy – Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard