Question

A compound of C and H consists of 94.34% C and 5.66% H, by mass. The molecular mass of the compound is found to be 178 u. What is its molecular formula? (higher multiplier for this one)

Answer 1

Step-by-step explanation:

mass ratio of C and H = 94.34 : 5.66

mole ratio of C and H = 94.34 /12 : 5.66 /1

= 7.86 : 5.66

= 1.388 : 1

= 6.94 : 5

or , 7 : 5

So empirical formula = C₇ H₅

Let the molecular formula = ( C₇ H₅)ₙ where n is an integer

Molecular weight = n ( 7 x 12 + 5 x 1 )

89 n = 178

n = 2

mol formula = C₁₄ H₁₀.