Question

The cooling curve below represents the cooling of a sample of gas. According to the cooling curve, what phase(s) would you expect to observe when the substance is at a temperature of 275 Kelvin?

Answer 1

A line graph showing the cooling curve of a substance being cooled from the gas phase all the way down to the solid phase. The substance starts at a temperature around 450 K and ends at a temperature around 250 K. First, there is a decline with a negative slope from 450 K to 375 K, followed by a horizontal region at 375 K. Then there is another decline with a negative slope from 375 K to 275 K, followed by another horizontal region at 275 K. The end of the cooling curve shows another decline with a negative slope from 275 K to 250 K.


gas and liquid

liquid

liquid and solid

solid

Answer 2

@ganeshie8 @SolomonZelman @Loser66

Answer 3

hint : temperature stays fixed during a phase change

Answer 4

Solid?

Answer 5

Look at the graph - the graph is going flat two times, right ?

Answer 6

Yes.

Answer 7

the temperature is continuously decreasing, but at t = 375, the temperature is not decreasing for some time.

Answer 8

So at t = 375, we have "gas --> liquid" phase CHANGE

Answer 9

isn't it asking for 275?

Answer 10

again at t = 275, the graph is going flat indicating a phase change

Answer 11

so at t = 275, it has to be "liquid --> solid" phase CHANGE

Answer 12

So it's a solid?

Answer 13

the liquid is hardening and getting a shape... so you will see `both liquid and solid` at t=275

Answer 14

ty