Calculate the mass of 12 * 10 ^ 23 H2S molecules.

N (H2S) = 12 * 10’23 molecules.
Let’s determine the mass of hydrogen sulfide. We write down the solution.
We use the following formula.
N = n * Na.
Where N is the number of molecules.
n is the amount of substance.
Na – Avogardo’s number, constant equal to 6.02 * 10’23.
n = N / Na = 12 * 10’23 / 6.02 * 10’23 = 1.993 mol.
Next, we find the mass of hydrogen sulfide.
n = m / M.
Where n is the amount of substance.
m is the mass of the substance.
M is the molar mass of the substance.
M (H2S) = 1 * 2 + 32 = 34 g / mol.
m = n * M = 1.993 * 34 = 67.8 g.
Answer: the mass of hydrogen sulfide is 67.8 g.