Question

The empirical formula of an organic compound
containing carbon and hydrogen is CH, The mass
of one litre of this organic gas is exactly equal to
that of one litre of N, at same temperature and
pressure. Therefore, the molecular formula of the
organic gas is -
(1)c2h4
(2)C3h6
(3) C6h12
(4)C4h8​

Answer 1

Answer:

option A ) C2H4

Explanation:

PV=nRT

for gas with empirical formula CH2 ...{according to optins the empirical formula must be CH2 instead of CH}

P(1) V(1) = n(1) × R × T(1).........1

for N2 gas ...

P(2)×V(2) = n(2) × R T(2).........2

given ,

P(1) = P(2)

T(1)= T(2)

V(1) = V(2)

m(1) = m(2)

dividing equation 1 by 2

we get,

n(1) = n(2)

m(1) ÷ M(1) = m(2) ÷ M(2) ...{M= molar mass}

as m(1) = m(2)

we have , M(1) = M(2)

=> M(1) = 28

also M(1) = x × ( 12+ 2×1 )......{ let formula of gas be (CH2)x }

=> 28 = 14x

=> x= 2

molecular formula = (CH2)2

=> molecular formula = C2H4