Answer to Question #206171 in Chemistry for Carl Jewel Montes

Question

How many molecules of hydrogen gas are there in 8.32 g of Hepatanoic acid?

Molar Mass of the Acid = 130.182 g/mol

Molar Mass of Hydrogen = 1.008 g/mol

Answer 1

Solution:

Heptanoic acid = C₇H₁₄O₂

Hydrogen gas = H₂

C₇H₁₄O₂ → 7H₂

According to the scheme above: n(C₇H₁₄O₂) = n(H₂)/7

Thus:

(8.32 g C₇H₁₄O₂) × (1 mol C₇H₁₄O₂ / 130.182 g C₇H₁₄O₂) × (7 mol H₂ / 1 mol C₇H₁₄O₂) = 0.4474 mol H₂

One mole of any substance contains 6.022×10²³ atoms/molecules.

Therefore,

Number of H₂ molecules = (0.4474 mol) × (6.022×10²³ molecules / 1 mol) = 2.69×10²³ H₂ molecules

Answer: 2.69×10²³ molecules of hydrogen gas (H₂).