A sample of sulfur dioxide occupies a volume of 652 mL at 40°C and 720 mmHg. What will the volume be at STP?

Question

hi pls someone help me to solve this one using Combined Gas Law formula

Answer 1

Hello, Shin,

Since there is no change in the moles between the two states, we can use:

P1V1/T1 = P2V2/T2

We are going from one state of P and T to STP, which is 760 mmHg and 0^oC. Remember to convert all temperatures to Kelvin by adding 273.15.

Rearrange to solve for the unknown, V2:

V2 = V1(T2/T1)(P1/P2)

Lable the data and enter it carefully. Note the manner in which I express the temperature and pressure conditions as ratios. It helps us understand what to expect. In this problem, we are increasing pressure and lowering temperature. Therefore, (P1/P2) < 1, and (T2/T1) >1. They oppose each other, so it is hard to predict the direction of the outcome, but we might expect a decrease from the original volume, judging by the ratios

Enter the data. The arrangement allows easy cancellation of units, leaving only ml, which is what we want.

I obtained a final volume of 539 ml.

Bob