Question

A sample of gas at 25ºc has a volume of 11 l and exerts a pressure of 660 mm hg. how many moles of gas are in the sample?

Answer 1

The moles of the gas in the sample is 0.391 moles

calculation
by use of ideal gas equation, that is Pv=nRT
where n is number of moles
P(pressure)= 660 mmhg
R(gas constant) = 62.364 l.mmhg/mol.K
T(temperature)= 25 +273 = 298 k

by making n the subject of the formula

n= Pv/ RT

n is therefore= (660mm hg x11 L)/( 62.364 L.mmhg/mol.k x298 K) = 0.391 moles