## Calculate the total energy, in kilojoules, that is needed to turn a 46 g block of ice at -25 degrees C into water vapor at 100 degrees

Question

Calculate the total energy, in kilojoules, that is needed to turn a 46 g block
of ice at -25 degrees C into water vapor at 100 degrees C.

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2 months 2021-07-23T00:43:30+00:00 1 Answers 3 views 0

1. Answer: The amount of heat absorbed is 141.004 kJ.

Explanation:

In order to calculate the amount of heat released while converting given amount of steam (gaseous state) to ice (solid state), few processes are involved:

(1):

(2):

(3):

(4):

Calculating the heat absorbed for the process having the same temperature:

……(i)

where,

q is the amount of heat absorbed, m is the mass of sample and is the enthalpy of fusion or vaporization

Calculating the heat released for the process having different temperature:

……(ii)

where,

= specific heat of solid or liquid

are final and initial temperatures respectively

• For process 1:

We are given:

Putting values in equation (i), we get:

• For process 2:

We are given:

Putting values in equation (i), we get:

• For process 3:

We are given:

Putting values in equation (i), we get:

• For process 4:

We are given:

Putting values in equation (i), we get:

Calculating the total amount of heat released:

(Conversion factor: 1 kJ = 1000J)

Hence, the amount of heat absorbed is 141.004 kJ.