Question

a gobar gas plant produces methane and supplies to the families. if a family requires 15000kJ of energy per day, how many days will the quota of 10kg will last. (∆H of CH4=-1665kJ/mol).

Answer 1

Answer:- 10 kg quota of the gas would last in 69 days

Solution:- It's given that energy requirement of a family is 15000 kJ per day. The quota that is availability of methane gas is 10 kg. Also, delta H for methane is given as -1665 kJ per mol. It means 1665 kJ of energy is produced by the combustion of 1 mol of methane.

We could solve it easily using dimensional analysis as:

$10kg CH_4(\frac{1000g}{1kg})(\frac{1mol CH_4}{16g CH_4})(\frac{1665 kJ}{1 mol CH_4})(\frac{1 day}{15000 kJ})$

= 69 days

So, 10 kg quota of the gas would last in 69 days.

Answer 2

16g CH4 ------------ 1665kJ

So 10×10^3g ----------- 104.0625×10^4 kJ

15000kJ ------------ 1 day

So 104.0625×10^4 ------------ 0.0069375×10^4 days

= 69 days