JEE MAIN - Chemistry (2021 - 18th March Morning Shift - No. 24)
Complete combustion of 3g of ethane gives x $$\times$$ 1022 molecules of water. The value of x is __________. (Round off to the Nearest Integer). [Use : NA = 6.023 $$\times$$ 1023; Atomic masses in u : C : 12.0; O : 16.0; H : 1.0]
Answer
18
Explanation
$${C_2}{H_6} + {7 \over 2}{O_2}\buildrel {} \over
\longrightarrow 2C{O_{\,2}} + 3{H_2}O$$
Here, $${C_2}{H_6} = 3gm = {3 \over {30}} = 0.1$$ mol
From 1 mol C2H6 we get 3 mol H2O
$$ \therefore $$ From 0.1 mol C2H6 we get = 3 $$\times$$ 0.1 mol H2O
$$ \therefore $$ Moles of H2O = 0.3
= 0.3 $$\times$$ 6.023 $$\times$$ 1023 molecules
= 1.8069 $$\times$$ 1023 molecules
= 18.069 $$\times$$ 1022 molecules
Here, $${C_2}{H_6} = 3gm = {3 \over {30}} = 0.1$$ mol
From 1 mol C2H6 we get 3 mol H2O
$$ \therefore $$ From 0.1 mol C2H6 we get = 3 $$\times$$ 0.1 mol H2O
$$ \therefore $$ Moles of H2O = 0.3
= 0.3 $$\times$$ 6.023 $$\times$$ 1023 molecules
= 1.8069 $$\times$$ 1023 molecules
= 18.069 $$\times$$ 1022 molecules
Comments (0)
