Chapter 5, Problem 24PS

### Chemistry & Chemical Reactivity

10th Edition
John C. Kotz + 3 others
ISBN: 9781337399074

Chapter
Section

### Chemistry & Chemical Reactivity

10th Edition
John C. Kotz + 3 others
ISBN: 9781337399074
Textbook Problem

# A 25.0-mL sample of benzene at 19.9 °C was cooled to its melting point, 5.5 °C, and then frozen How much energy was given off as heat in this process? (The density of benzene is 0.80 g/mL, its specific heat capacity is 1.74 J/g · K, and its heat of fusion is 127 J/g.)

Interpretation Introduction

Interpretation:

The amount of released in the process has to be calculated.

Concept Introduction:

Heat energy required to raise the temperature of 1g of substance by 1k.Energy gained or lost can be calculated using the below equation.

q=C×m×ΔT

Where,

q= energy gained or lost for a given mass of substance (m),

C =specific heat capacity

ΔT= change in temperature

Explanation

Given,

â€‚Â Density of benzene=0.80g/mL

â€‚Â Mass of benzene = Density Ã— volume

Substitute in the given equation as

â€‚Â Mass of benzene=0.80g/mLÃ—25mL =20g

â€‚Â Melting point=5.50C

â€‚Â Heat of fusion of benzene=127J/g

To decrease the temperature of 19.90C-5.50C

â€‚Â q=CÃ—mÃ—Î”T

Substitute in the above equation as

â€‚Â q1 =1

### Still sussing out bartleby?

Check out a sample textbook solution.

See a sample solution

#### The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started