Question

0.1 mole carbohydrate with empirical formula CH2O contain 1 kg of hydrogen what is it's molecular formula

Answer 1

Let molecular formula (CH2o)n
In one mole of carbohydrate there is 2n g of hydrogen present.
So, 0.1 mole of carbohydrate there is 2n/1*0.1 g of hydrogen which is equal to 1g (from question)
2n * 0.1 = 1
n = 5
Molecular formula = C5H10O5

Hope it helps you. : )

Answer 2

The empirical formula for the given carbohydrate is- CH2O

We know that,

Molecular formula = empirical formula * n-factor

Now,

0.1 mole of carbohydrate -> 1 kg of Hydrogen

1 mole of carbohydrate -> {(1/0.1) * 1} kg of Hydrogen

= 10 Kg

10 kg of Hydrogen would denote 10 moles of hydrogen in 1 mole of carbohydrate.

As, 1 molecule of carbohydrate shows the presence of 2 atoms of hydrogen in it, the n-factor here would be 10/2= 5

So,

Molecular formula = empirical formula * n-factor

= (CH2O) * 5

= C5H10O5

Hence the molecular formula for the carbohydrate is C5H10O5.