Question 1

Which of the following best describes a compound?

Accepted Answer

A substance composed of two or more elements chemically combined in a fixed ratio.

Question 2

Which of the following is an example of a homogeneous mixture?

Accepted Answer

Brass (an alloy of copper and zinc)

Question 3

A sample of air is best classified as:

Accepted Answer

A homogeneous mixture

Question 4

Which of the following statements about solids is correct?

Accepted Answer

Solids have a definite shape and volume.

Question 5

Which of the following is a chemical change?

Accepted Answer

Iron rusting in an old car

Question 6

Convert a body temperature of $$39.0\ ^\circ\mathrm{C} to $$degrees Fahrenheit. Use the formula $$F = 1.8C + 32.$$

Accepted Answer

$$102.2\ ^\circ\mathrm{F}$$

Question 7

Which of the following best describes potential energy?

Accepted Answer

Energy stored in chemical bonds or due to position

Question 8

How many kilocalories are in a food sample containing 10 g of carbohydrate, 5 g of fat, and 3 g of protein? (Carbohydrate: $$4\ \mathrm{kcal/g}$$, Fat: $$9\ \mathrm{kcal/g}$$, Protein: $$4\ \mathrm{kcal/g})$$

Accepted Answer

81 kcal

Question 9

A 24.8 g sample of metal absorbs 275 J of energy, raising its temperature from $$21.0\ ^\circ\mathrm{C} to$$ $$56.0\ ^\circ\mathrm{C}. $$What is the specific heat ($$c) of $$the metal? Use $$q = mc\Delta T.$$

Accepted Answer

$$0.32\ \mathrm{J/g\ ^\circ C}$$

Question 10

How many joules are needed to melt 32.0 g of ice at $$0\ ^\circ\mathrm{C}$$? (Heat of fusion for water: $$334\ \mathrm{J/g})$$

Accepted Answer

$$10,688\ \mathrm{J}$$

Question 11

Which process is an example of sublimation?

Accepted Answer

Dry ice changing directly from solid to gas

Question 12

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

Accepted Answer

A constant temperature and a change of state

Question 13

Which of the following statements about the Kelvin temperature scale is correct?

Accepted Answer

Absolute zero is $$0\ \mathrm{K}$$, and there are no negative values.

Question 14

How many calories are obtained from a pat of butter if it provides 150 J of energy when metabolized? ($$1\ \mathrm{cal} = 4.184\ \mathrm{J})$$

Accepted Answer

36 cal

Question 15

Which of the following is a physical property?

Accepted Answer

Copper is an excellent conductor of electricity

Question 16

When water vapor condenses to liquid water, the process is:

Accepted Answer

Exothermic and releases heat

Question 17

Which of the following best explains why sand in the desert is hot during the day and cool at night?

Accepted Answer

Sand has a low specific heat.

Question 18

A 175 g sample of steam at $$100\ ^\circ\mathrm{C}$$ condenses and then freezes at $$0\ ^\circ\mathrm{C}. $$How much energy is released? (Heat of vaporization: $$2260\ \mathrm{J/g}$$, Heat of fusion: $$334\ \mathrm{J/g})$$

Accepted Answer

528 kJ

Chapter 3: Matter and Energy – Study Notes for GOB Chemistry

Guida di studio - Domande di pratica

Study guide - Flashcard