22.4 dm^3 of each gas at stp has different mass but the same number of molecule. justify.
( kindly )

At STP, a given volume has the same number of moles. So, no. of moles= 22.4÷24= 0.93333mol (5 s.f.)

Number of molecules= no. of moles × 6×10^23 , which would give us the same number of molecules since the number of moles are the same.

However, mass of a gas depends on the mr of the gas.

This is because the formula for the mass of a gas is mole× mr.

Since different gases would have different mr, mass would differ.

answer; 10 foot-candles