Can someone Help me with these questions please? ?

Question

Find the volume in liters for a .35 mol sample of a gas at 98 kPa of pressure and 333 K?

42 L

.10 L

11 L

9.9 L

Find the pressure created in torrs when a .0078 mol sample of a gas occupies 775 mL at 344 K? 

220 torr

15000 torr

760 torr

.22 torr

How many times faster would a sample of He effuse than an equivalent sample of CO?

2.6

.38

7.0

3.3

Answer 1

V = nRT / P = (0.35 mol) x (8.3144626 L kPa/K mol) x (333 K) / (98 kPa) = 9.888 L =

9.9 L

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P = nRT / V = (0.0078 mol) x (62.36367 L torr/K mol) x (344 K) / (0.775 L) =

215.8 torr = 220 torr

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√ ((28.0101 g/mol CO) / (4.002602 g He/mol)) = 2.645 = 2.6 times