WHAT WOULD BE PERCENTAGE COMPOSITION BY VOLUME OF CO AND CH4 ,WHOSE 10.5 ml REQUIRES 9 ml OXYGEN FOR COMPLETE COMBUSTION? - CO=80% AND CH4=20%
- CO=76.2% AND CH4=23.8%
- CO=66% AND CH4=34%
- CO=90% AND CH4 =10%
Let us write two separate combustion reactions, one for CO and the other for CH4 reacting with O2 .
2CO(g) + O2 2CO2 ... eq. 1.
2mol ......1mol ....2 mol
CH4 (g) + 2O2 CO2 + H2O(l) ...... eq. 2
1 mol.......2 mol...... 1mol......zero (liquid)
Let us assume that out of 10.5 ml of mixture, the volume of CO = x ml, and so the volume of CH4 =(10.5-x)ml
From eq. 1,
2mol of CO produces 2 mol of CO2 gas, so x mol of CO will produce x ml of CO2 gas.
Again 2 ml of CO requires 1 ml of O2, so x ml of CO will require x/2 ml of O2
Further we have, from eq. 2,
1 mol of CH4 produces 1 mol of CO2 gas so, (10.5-x)ml of CH4 will produce (10.5-x) ml of CO2.
Again 1 mol of CH4 requires 2 mol of O2 gas so, (10.5-x)ml of CH4 requires 2(10.5-x)ml of O2 gas
The volume of oxygen consumed by both reactions=x/2 + 2(10.5-x)=(42-3x)/2
We are provided with volume of oxygen consumed so,
(42-3x)/2 = 9 ml
42 - 3x = 18
Or, 3x = 42-18 = 24
Hence, x = 8 ml
So, CO = 8 ml
and, CH4 = 10.5-8 =2.5 ml
So, %age composition of CO = (8/ 10.5) x 100 = 76.2%
%age composition of CH4 = (2.5/ 10.5) x 100 = 23.8 %
2CO(g) + O2 2CO2 ... eq. 1.
2mol ......1mol ....2 mol
CH4 (g) + 2O2 CO2 + H2O(l) ...... eq. 2
1 mol.......2 mol...... 1mol......zero (liquid)
Let us assume that out of 10.5 ml of mixture, the volume of CO = x ml, and so the volume of CH4 =(10.5-x)ml
From eq. 1,
2mol of CO produces 2 mol of CO2 gas, so x mol of CO will produce x ml of CO2 gas.
Again 2 ml of CO requires 1 ml of O2, so x ml of CO will require x/2 ml of O2
Further we have, from eq. 2,
1 mol of CH4 produces 1 mol of CO2 gas so, (10.5-x)ml of CH4 will produce (10.5-x) ml of CO2.
Again 1 mol of CH4 requires 2 mol of O2 gas so, (10.5-x)ml of CH4 requires 2(10.5-x)ml of O2 gas
The volume of oxygen consumed by both reactions=x/2 + 2(10.5-x)=(42-3x)/2
We are provided with volume of oxygen consumed so,
(42-3x)/2 = 9 ml
42 - 3x = 18
Or, 3x = 42-18 = 24
Hence, x = 8 ml
So, CO = 8 ml
and, CH4 = 10.5-8 =2.5 ml
So, %age composition of CO = (8/ 10.5) x 100 = 76.2%
%age composition of CH4 = (2.5/ 10.5) x 100 = 23.8 %