How many moles of hidrogen sulfide are contained in a 35.0 g sample of these gas ?
We'll recall the chemical formula of the chemical compound called hydrogen sulfide: H2S
Since the volume of the gas is not specified, we'll not apply the standard molar volume formula to determine the number of moles of the gas.
We'll calculate the molar mass of hydrogen sulfide. For this reason, we need to know the atomic mass of the chemical elements present in this compound.
The atomic mass of hydrogen is:1g/mole
The atomic mass of sulphur is: 16 atoms
Molar mass: 2 atoms*1g/mole + 32 = 34grams/mole
Since the molar mass of H2S is 34 grams/mole, then 35 g of this gas does have 35 - 34 = 1 mole.