Question 1

Which of the following best describes a homogeneous mixture?

Accepted Answer

A mixture in which the composition is uniform throughout and the different parts are not visible.

Question 2

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

Accepted Answer

Iron rusting in an old car.

Question 3

A sample of metal with a mass of 24.8 g absorbs 275 J of energy, causing its temperature to rise from $$15.0\ ^\circ\mathrm{C} to$$ $$19.3\ ^\circ\mathrm{C}. $$What is the specific heat of the metal?

$$	ext{Specific heat} = \dfrac{	ext{heat}}{	ext{mass} 	imes \Delta T}$$

Accepted Answer

$$2.6\ \dfrac{\mathrm{J}}{\mathrm{g}\cdot ^\circ\mathrm{C}}$$

Question 4

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

Accepted Answer

The Kelvin scale has no negative temperatures and absolute zero is $$0\ \mathrm{K}.$$

Question 5

How many kilojoules are released when $$50.0\ \mathrm{g} of $$steam condenses at $$100\ ^\circ\mathrm{C}$$? (Heat of vaporization for water is $$2260\ \mathrm{J/g})$$

Accepted Answer

$$113\ \mathrm{kJ}$$

Question 6

Which of the following is a physical property?

Accepted Answer

Ice melts in the sun.

Question 7

A cup of whole milk contains $$13\ \mathrm{g} of $$carbohydrate, $$9.0\ \mathrm{g} of $$fat, and $$9.0\ \mathrm{g} of $$protein. Using the typical energy values ($$4\ \mathrm{kcal/g}$$ for carbohydrate, $$9\ \mathrm{kcal/g}$$ for fat, $$4\ \mathrm{kcal/g}$$ for protein), how many kilocalories does a cup of whole milk contain?

Accepted Answer

$$170\ \mathrm{kcal}$$

Question 8

Which of the following best describes potential energy?

Accepted Answer

Energy stored for use at a later time, determined by position or chemical composition.

Question 9

Which of the following is a heterogeneous mixture?

Accepted Answer

Hot fudge sundae

Question 10

What is the temperature in degrees Fahrenheit of a person with hypothermia if their body temperature is $$34.0\ ^\circ\mathrm{C}$$?

$$T_F = 1.8(T_C) + 32$$

Accepted Answer

$$93.2\ ^\circ\mathrm{F}$$

Question 11

Which of the following processes is an example of sublimation?

Accepted Answer

Dry ice changing directly from solid to gas.

Question 12

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

Accepted Answer

$$36\ \mathrm{cal}$$

Question 13

Which of the following statements about specific heat is correct?

Accepted Answer

Specific heat is the amount of heat that raises the temperature of exactly $$1\ \mathrm{g} of a $$substance by $$1\ ^\circ\mathrm{C}.$$

Question 14

Which of the following best describes a compound?

Accepted Answer

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

Question 15

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

Accepted Answer

A constant temperature and a change of state.

Question 16

Which of the following is true about the energy changes when water freezes?

Accepted Answer

Heat is removed from the water.

Question 17

Which of the following is an example of kinetic energy?

Accepted Answer

Rollerblading

Question 18

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

Accepted Answer

$$T_K = T_C + 273$$

Chapter 3: Matter and Energy – GOB Chemistry Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard