Answer:
We can conclude that the gas evolved was carbon dioxide.
Explanation:
On an efficient combustion that is on complete combustion of carbon, carbon dioxide is produced.
(Complete combustion)
But during incomplete combustion of carbon results in formation of carbon monoxide (poisons gas).
(Incomplete combustion)
Theoretical value density of carbon dioxide = 1.80 g/L
Theoretical value density of carbon monoxide = 1.15 g/L
Experimental measured density of the gas = 1.77 g/L
1.77 g/L ≈ 1.80 g/L
Since, the experimental measured density of the gas is more closer to theoretical value of density of carbon dioxide from which we can conclude that 'the gas evolved after the combustion of carbon impurity was carbon dioxide'.