Question

As the temperature of a sample of gas falls from 45.0•C to 30.0•C, its pressure falls to 300. mmHg. If the volume did not change, what was the original gas pressure (P1)?

A) 285 mmHg
B) 315 mmHg
C) 400 mmHg
D) 615 mmHg

Answer 1

315 mmHg

Step-by-step explanation:

The relationship between pressure and temperature looks like this

P1/T1 = P2/T2

What this means is that the first pressure divided by the first temperature is equal to the second pressure divided by the second temperature.

In this instance, we can divide the unknown by 318 K (to find the temp in K add 273 to the degrees Celsius) and set that equal to 300 mmHg divided by 303 K.

x / 318 = 300 / 303

x = 315 mmHg