Select the correct answer.

What is the heat required to vaporize 650 grams of a liquid with a heat of vaporization of 723 joules/gram?

A. 0.90 J
B. 1.1 J
C. 73 J
D. 1,370 J
E. 470,000 J



Answer :

To determine the heat required to vaporize 650 grams of a liquid with a heat of vaporization of 723 joules/gram, follow these steps:

1. Identify the given data:
- Mass of the liquid ([tex]\( m \)[/tex]): [tex]\(650\)[/tex] grams
- Heat of vaporization ([tex]\( L \)[/tex]): [tex]\(723\)[/tex] joules/gram

2. Use the formula for calculating the heat required to vaporize a given mass:
[tex]\[ Q = m \times L \][/tex]
where [tex]\( Q \)[/tex] is the heat required, [tex]\( m \)[/tex] is the mass, and [tex]\( L \)[/tex] is the heat of vaporization.

3. Substitute the values into the formula:
[tex]\[ Q = 650 \, \text{grams} \times 723 \, \text{joules/gram} \][/tex]

4. Calculate the result:
[tex]\[ Q = 469950 \, \text{joules} \][/tex]

Thus, the heat required to vaporize 650 grams of the liquid is [tex]\( 469950 \)[/tex] joules.

Given the options:
- A: [tex]\( 0.90 \, \text{J} \)[/tex]
- B: [tex]\( 1.1 \, \text{J} \)[/tex]
- C: [tex]\( 73 \, \text{J} \)[/tex]
- D: [tex]\( 1,370 \, \text{J} \)[/tex]
- E: [tex]\( 470,000 \, \text{J} \)[/tex]

The correct answer, rounding to match the options provided, is:
E. 470,000 J.