A 1.20-L contains 1.10 g of an unknown gas at STP . what is the molecular...

A 1.20-L contains 1.10 g of an unknown gas at STP . what is the molecular weight of the unknown gas?

Solutions

Expert Solution

At STP 1 mole of any ideal gas has a volume of 22.4 L

So moles unknown gas = volume / 22.4 L/mol

= 1.20 L / 22.4 L/mol

= 0.05357 moles

So now we know that 0.05357 moles of gas has a mass of 1.10 g

moles = mass / molar mass

Therefore molar mass = mass / moles

molar mass = 1.10 g / 0.05357 moles

= 20.5 g/mol

Therefore, the molecular weight of unknown gas is 20.5 g/mol.

queen_honey_blossom answered 9 months ago

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