A sample of hydrogen sulfide has a mass of 73.00 g. Calculate the number of hydrogen sulfide molecules in the sample.

1.29×10²⁴ molecules.

Explanation:

From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ molecules. Thus, 1 mole of Hydrogen sulfide (H2S) contains 6.02×10²³ molecules.

Next, we shall determine the mass of 1 mole of H2S. This is illustrated below:

1 mole of H2S = (2×1) + 32 = 34 g

Finally, we shall determine the number of molecules in 73 g of H2S as follow:

34 g of H2S contains 6.02×10²³ molecules.

Therefore, 73 g of H2S will contain =

(73 × 6.02×10²³) /34 = 1.29×10²⁴ molecules.

Thus, 73 g of H2S will contain 1.29×10²⁴ molecules.