Q: Which of the following is the correct relationship between calories and joules?

$$1\ \text{cal} = 4.184\ \text{J}$$

Question 1

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

Accepted Answer

Burning a piece of paper

Question 2

A sample of matter is uniform throughout and has a fixed composition. Which classification best describes this sample?

Accepted Answer

Pure substance

Question 3

Which of the following statements about elements and compounds is correct?

Accepted Answer

Compounds are made of two or more elements chemically combined in a fixed ratio.

Question 4

Which of the following is a physical property?

Accepted Answer

Boiling point

Question 5

A student mixes sand and salt together. Which method would best separate the two substances?

Accepted Answer

Filtration

Question 6

Which of the following best describes a homogeneous mixture?

Accepted Answer

A mixture in which the composition is uniform throughout the sample

Question 7

Which of the following is the correct formula to convert a temperature from Celsius to Fahrenheit?

Accepted Answer

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

Question 8

A metal sample with a mass of 50.0 g absorbs 418 J of heat, causing its temperature to increase by $$10.0^{\circ}C$. What is the specific heat of the metal in J/g$$^{\circ}$$C$$?

Accepted Answer

$$0.84\ J/g$$^{\circ}$$C$$

Question 9

Which of the following best describes the particles in a gas?

Accepted Answer

Particles are far apart and move at high speeds

Question 10

Which of the following is a correct statement about physical and chemical changes?

Accepted Answer

Physical changes can often be reversed by physical means

Question 11

A 100.0 g sample of water at $$25^{\circ}C$ absorbs 4184 J of heat. What is the final temperature of the water? (Specific heat of water = 4.184$$\ $$J/g^{\circ}C$)

Accepted Answer

$$35^{\circ}C$

Question 12

Which of the following is NOT a pure substance?

Accepted Answer

Air

Question 13

Which of the following best describes potential energy?

Accepted Answer

Energy associated with the position or composition of a substance

Question 14

Which of the following is the correct relationship between calories and joules?

Accepted Answer

$$1\ 	ext{cal} = 4.184\ 	ext{J}$$

Question 15

Which of the following is a chemical property?

Accepted Answer

Ability to react with oxygen

Question 16

A sample of ethanol (C$$_2H$_5OH) $$has a mass of 10.0 g and absorbs 246 J of heat, raising its temperature by $$10.0^{\circ}C$. What is the specific heat of ethanol in J/g$$^{\circ}$$C$$?

Accepted Answer

$$2.46\ J/g$$^{\circ}$$C$$

Question 17

Which of the following best explains why water is considered a compound?

Accepted Answer

It consists of two elements chemically combined in a fixed ratio

Question 18

Which of the following is the correct formula for calculating specific heat?

Accepted Answer

$$SH = \dfrac{q}{m \Delta T}$$

Question 19

A 25.0 g sample of a metal at $$100.0^{\circ}C$ is placed in 100.0 g of water at 25.0$$^{\circ}$$C. $$The final temperature of the system is $$28.0^{\circ}C$. If the specific heat of water is 4.184$$\ $$J/g^{\circ}C$, what is the specific heat of the metal? (Assume no heat loss to the surroundings.)

Accepted Answer

$$0.28\ J/g$$^{\circ}$$C$$

Question 20

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

Accepted Answer

A chemical change results in the formation of new substances, while a physical change does not.

Introduction to Chemistry: Matter, Properties, Energy, and Measurement

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