Question

a 28 g sample of which gas will have a dry volume of about 44.8 l at stp N2 or CO

Answer 1

Given,

Mass of gas sample = 28 g

Volume of gas = 44.8 L

we know that , At STP ,

1 mole of gas occupies 22.4 L ==> 22.4 L of gas means ------> 1 mole of gas

==> 44.8 L of gas means ------> (1/22.4) * 44.8 = 2 mole of gas. ---------(1)

Now, molar mass of N2 = 28 g/mol

and molar mass of CO = 28 g/mol

Therefore,

no.of moles of N2 gas = mass of N2 / molar mass = 28/28 = 1 mole ( if the given gas is N2)

and no.of moles of CO = mass of CO / molar mass of CO = 28/28 = 1mole ( if the given gass is CO)

As per our previous calculation i.e., (1) no. of moles must be 2 moles.

But with 28 g of sample we are having either 1 mole of N2 or 1 mole of CO

Therefore, None of the given two gases will have a dry volume of about 44.8 L at STP.