Question

The empirical formula of pyrogallol is C2H2O. Its molar mass is 126 g mol-1. What is the molecular formula?C4H4O2C2H6O3C6H6O3C2H2O

Answer 1

Answer:

The molecular formula of pyrogallol is: C6H6O3

Explanation:

Step 1: Data given

Empirical formula of pyrogallol is C2H2O

Molar mass of pyrogallol = 126 g/mol

Molar mass of Carbon (C) = 12 g/mol

Molar mass of hydrogen (H) = 1.01 g/mol

Molar mass of oxygen (O) = 16 g/mol

Step 2: Calculate molar mass of the empirical formula

2*12 + 2*1+ 16 = 42 g/mol

Step 3: Calculate the molecular formula

To find the molecular formule , we should multiply the empirical formula by n

n can be found by dividing molar mass of pyrogallol by the molar mass of the empirical formula

n = 126 g/mol / 42 g/mol ≈ 3

We should mulitply the empirica lformula by 3

3*(C2H2O) gives C6H6O3

if we calculate the molar mass now:

6*12 +6*1 + 3*16 = 126 g/mol

The molecular formula of pyrogallol is: C6H6O3