What volume will 17 g of hydrogen sulfide take? How many molecules are there in this volume?

1. Let’s convert the mass of hydrogen sulfide into the amount:

n (H2S) = m (H2S) / M (H2S) = 17 g / 34 g / mol = 0.5 mol.

2. Find the volume of the substance (Vm – molar volume, constant equal to 22.4 mol / l):

V (H2S) = n (H2S) * Vm = 0.5 mol * 22.4 mol / L = 11.2 L.

3. Find the number of molecules in a given portion of the substance (NA is Avogadro’s number, a constant equal to 6.02 * 10-23 mol-):

N (H2S) = n (H2S) * NA = 0.5 mol * 6.02 * 10-23 mol – = 3.01 * 10-23.

Answer: V (H2S) = 11.2 l; N (H2S) = 3.01 * 10-23.