# Chlorine is widely used to purify municipal water supplies and to treat swimming pool water. Suppose that the volume ?

Chlorine is widely used to purify municipal water supplies and to treat swimming pool water. Suppose that the volume of a particular sample of Cl2 gas is 8.70 L at 895 torr and 25 ∘C.

How many grams of Cl2 are in the sample?

What volume will the Cl2 occupy at STP?

At what temperature will the volume be 14.50 L if the pressure is 873 torr?

At what pressure will the volume equal 5.50 L if the temperature is 58 ∘C?

### 1 Answer

- hcbiochemLv 71 month agoFavorite Answer
Use the ideal gas law: PV = n RT

Since all pressures are given in torr, use R = 62.37 L torr / mol K

895 torr (8.70 L) = n (62.37 L torr/molK) (298 K)

n = 0.419 mol Cl2

Mass Cl2 = 0.419 mol X 70.9 g/mol = 29.7 g Cl2

To calculate the volume of gas at STP, you can either calculate it using:P1V1/T1 = P2V2/T2 where P2 = 760 torr and T2= 273 K

Or, you can use the idea that at 1 atm pressure and 273 K, 1 mole of gas has a volume of 22.4 L. So,

0.419 mol X 22.4 L/mol = 9.38 L

P1V1/T1 = P2V2/T2

895 torr (8.70 L) / 298 K = 873 (14.50 L) / T2

T2 = 484 K = 211 C

Use this same formula to solve the last one.