Question

. Ascorbic acid, also known as vitamin C, has a percentage composition of 40.9%C, 4.58%H, and 54.5%O. If its molecular is 176.1 g, what is its molecular formula

Answer 1

Answer:

C₆H₈O₆

Explanation:

From the question given above, the following data were obtained:

Percentage of Carbon (C) = 40.9%

Percentage of Hydrogen (H) = 4.58%

Percentage of Oxygen (O) = 54.5%

Molecular mass of compound = 176.1 g/mol

Molecular formula of Ascorbic acid =.?

Next, we shall determine the empirical formula for the compound. This can be obtained as follow:

C = 40.9%

H = 4.58%

O = 54.5%

Divide by their molar mass

C = 40.9 / 12 = 3.41

H = 4.58 / 1 = 4.58

O = 54.5 / 16 = 3.41

Divide by the smallest

C = 3.408 / 3.41 = 1

H = 4.58 / 3.41 = 1.3

O = 3.406 / 3.41 = 1

Multiply by 3 to express in whole number

C = 1 × 3 = 3

H = 1.3 × 3 = 4

O = 1 × 3 = 3

Empirical formula for the compound is C₃H₄O₃

Finally, we shall determine the molecular formula of the compound. This can be obtained as follow:

Molecular mass of compound = 176.1 g/mol

Empirical formula => C₃H₄O₃

Molecular formula =?

Molecular formula => [C₃H₄O₃]ₙ

[C₃H₄O₃]ₙ = 176.1

[(12×3) + (1×4) + (16×3)]n = 176.1

[36 + 4 + 48]n = 176.1

88n = 176.1

Divide both side by 88

n = 176.1 / 88

n = 2

Molecular formula => [C₃H₄O₃]ₙ

Molecular formula => [C₃H₄O₃]₂

Molecular formula => C₆H₈O₆

Thus, the molecular formula for Ascorbic acid is C₆H₈O₆