Question

The substance krypton has the following properties normal melting point 115.9 K normal boiling point: 119.8 K triple point: 0.72 atm. 115.8 K critical point: 54.3 atm. 209.4 K A sample of krypton at a pressure of 1.00 atm and a temperature of 149.2 K is cooled at constant pressure to a temperature of 107.8 K Which of the following are true?
a) The final state of the substance is a solid
b) One or more phase changes will occur
c) The final state of the substance is a liquid
d) The sample is initially a gas
e) The solid initially present will vaporize.

Answer 1

Answer:

B. One or more phase change occur

C. the final state of substance is liquid

D. the sample initially gas

Explanation:

The pressure p = 1.00 atm

The temperature t = 149.2K

The temperature > 119.8K

119.8K being the normal boiling point.

This shows that the krypton is a gas

After it has cooled the pressure = 1.00 atm

The temperature T dropped to 107.8K

T < 115.9K

The melting point has been put as 115.9K

This is a liquid. The final state of the substance is a liquid. Since the temperature is less than the melting point and the pressure is 1.00 atm