Question

Determine the molecular formula for a compound that is 94.1% O and 5.9% H with a molar mass of 34 g.

Answer 1

answer:

H202

explanation:

By converting the mass % into grams

oxygen = 94.1 gm

hydrogen= 5.9gm

• moles of oxygen = weight/atm.wt = 94.1/ 16 = 5.88
• moles of hydrogen = weight/atm.wt= 5.9/1= 5.9
• simplest mole ratio of O : H = 1 : 1
• so the empirical formula is OH whose empirical mass is 17gm
• molecular mass given is 34gm
• mol.mass/emp.mass = n= 34/17 = 2
• so the molecular formula is H202