Question

# By the reaction of carbon and oxygen, a mixture of CO and CO2 is obtained. What is the composition of the mixture by mass obtained when 20 g of O2 reacts with 12 g of carbon?

A
CO : CO2 =21:11
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
CO : CO2 =11:21
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
CO : CO2 =21:22
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
CO : CO2 =42:11
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

## The correct option is A CO : CO2 =21:11The balanced chemical equations for the combustion reaction are as follows:2xC+xO2→2xCOyC+yO2→yCO2Total number of moles of C =2x+yTotal number of moles of oxygen = x+yThe molar masses of C and oxygen are 12 g/mol and 32 g/mol respectively.12 g of C corresponds to 1 mole and 20 g of oxygen corresponds to 2032=0.625 moles.Hence, 2x+y=1......(1) and x+y=0.625......(2)Substracting equation (2) from (1), we get(2x+y)−(x+y)=1−0.625x=0.375......(3)Substituting equation (3) in equation (2), we get0.375+y=0.625y=0.250The number of moles of CO formed are 2x=2(0.375)=0.75The number of moles of CO2 formed are y=0.250The molar masses of CO and CO2 are 28 g/mol and 44 g/mol respectively.The mass of CO formed is 0.75×28=21gThe mass of CO2 formed is 0.250×44=11g.Hence, the composition of the mixture is CO:CO2=21:11.

Suggest Corrections
1
Join BYJU'S Learning Program
Related Videos
Alkanes - Chemical Properties
CHEMISTRY
Watch in App
Explore more
Join BYJU'S Learning Program