Question

What is the likely identity of a gas at `273.15` `K`, whose mass is `7.5*g`, and which exerts a pressure of `1*"bar"`?

Answer 1

Well, let's try to address the molar mass of the gas........we get a range of possibilities.........

Explanation:

`"STP"` specifies a temperature of `273.15 K`, and an absolute pressure of exactly `100* kPa, "1 bar"`.

`n=(PV)/(RT)=(1*cancel"bar"xx5.6*cancelL)/(8.314xx10^(-2)cancelL*cancel"bar"*cancel(K^-1)*mol^-1xx273.15*cancelK)`

`=0.247*(mol^-1)^-1=0.247*mol`

And thus `(7.5*g)/(0.247*mol)=30.3*g*mol^-1`.

The gas is likely the homonuclear diatomic `N_2` or `O_2`.

Further data are needed to confirm the identity of the gas.