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12. How many moles of helium are needed to fill a balloon that has a volume of s

ID: 1037783 • Letter: 1

Question

12. How many moles of helium are needed to fill a balloon that has a volume of sAS L and a pressure of 820 min Hg at room temperature of 23?? Assume ideal gas behavior. 13. 2.358 g of a gas occupies 1,39 L at STP. What is the molar mass of the gas? b. What is the likely gas? 14. A sample of KCIO, gas that is collected over water. The volume of gas collected is 0.250L at 26°C and 765 torr total pressure. P (H:O) 25.21 torr. The reaction is 2 KCIO, >2 KCI+3 0: (g) a. How many moles of O are collected? b. How many grams of KCIO, were decomposed?

Explanation / Answer

Ans 12

Volume V = 5.45 L

Pressure P = 820 mmHg x 1atm/760mmHg = 1.0789 atm

Temperature T = 23 + 273.15 = 296.15 K

Gas constant R = 0.0821 L-atm/mol-K

Ideal gas equation

Moles of He = PV/RT

= 1.0789 x 5.45 / 0.0821 x 296.15

= 0.242 moles