Chapter 11, Problem 61A

Welding If 5.50 mol of calcium carbide $\left({\text{CaC}}_{\text{2}}\right)$ reacts with an excess of water, how many moles of acetylene $\left({\text{C}}_{\text{2}}{\text{H}}_{\text{2}}\right)$ , a gas used in welding, will be produced?
   ${\text{CaC}}_{\text{2}}\left(\text{s}\right){\text{ + 2H}}_{\text{2}}\text{O}\left(\text{l}\right)\to \text{Ca}{\left(\text{OH}\right)}_{\text{2}}\left(\text{aq}\right){\text{+ C}}_{\text{2}}{\text{H}}_{\text{2}}\left(\text{g}\right)$

Interpretation Introduction

Interpretation:

The number of moles of acetylene in reaction needs to be determined.

Concept introduction:

Mole − mole conversion used to find mole of any substance from mole of other substance in a balanced chemical equation.

Answer to Problem 61A

$5.50mole$ of acetylene will be produced.

Explanation of Solution

Balanced chemical equation is represented as follows:

$Ca{C}_2+2H_{2}O\underset{}{\overset{}{\to }}Ca{\left(OH\right)}_2+C_2{H}_2$

From balanced chemical mole equation, $1$ mole of $Ca{C}_2$ gives $1$ mole of acetylene thus, mole ratio is 1:1.

Therefore,

$5.50moleCa{C}_2$ produces $5.50$ mole of acetylene.

Conclusion

$5.50$ mole acetylene is produced from mole − mole conversion.