Question

Acetylene, used as a fuel in welding torches, is produced in a reaction between calcium carbide and water:
$Ca{C}_2+2H_{2}O\to Ca{\left(OH\right)}_2+C_2{H}_2$
How many grams of $C_2{H}_2$ are formed from 0.400 moles of $Ca{C}_2$?

• A. $0.400$
• B. $0.800$
• C. $4.00$
• D. $10.4$
• E. $26.0$

Answer 1

The correct option is D $10.4$

$Ca{C}_2+2H2O\to Ca(OH{)}_2+C_2{H}_2$
As per this balanced chemical equation 1 mol of $C_2{H}_2$ produces 1 mol of $C_2{H}_2$.
0.400 mol of $Ca{C}_2$ will produce 0.400 mol of $C_2{H}_2$.
As 1 mol of $C_2{H}_2$ has 26 g weight.
Hence, 0.400 mol produced has weight to be equal to the $0.4\times 26=10.4$ g.