Question

On heating 30g acetic acid and 69g ethyl alcohol 88g of ethyl acetate is obtained.how much ester will be obtained from heating 120g of acetic acid and 23g of ethyl alcohol ?​

Answer 1

Answer : The mass of ester obtained will be 127.11 grams.

Explanation :

Law of conservation of mass : It states that mass can neither be created nor be destroyed but it can only be transformed from one form to another form.

This also means that total mass on the reactant side must be equal to the total mass on the product side.

The balanced chemical reaction will be,

$CH_3COOH+C_2H_5OH\rightarrow C_2H_5COOCH_3+H_2O$

Mass of $CH_3COOH$ = 30 g

Mass of $C_2H_5OH$ = 69 g

Mass of $C_2H_5COOCH_3$ = 88 g

Now we have to calculate the mass of $H_2O$.

Mass of $H_2O$ = (Mass of $CH_3COOH$ + Mass of $C_2H_5OH$) - Mass of $C_2H_5COOCH_3$

Mass of $H_2O$ = (30g + 69g) - 88g = 11 g

Mass of $H_2O$ = 11 g

Now we have to calculate the ratio of mass of $C_2H_5COOCH_3$ and $H_2O$.

$\frac{\text{Mass of }C_2H_5COOCH_3}{\text{Mass of }H_2O}=\frac{88}{11}=\frac{8}{1}$

Given : Total mass on the reactant side = 120g + 23g = 143 g

Now we have to calculate the mass of ester $C_2H_5COOCH_3$ obtained from heating 120g of acetic acid and 23g of ethyl alcohol.

$\text{Mass of ester}=\frac{8}{9}\times \text{Total mass of reactant side}$

$\text{Mass of ester}=\frac{8}{9}\times 143g=127.11g$

Therefore, the mass of ester obtained will be 127.11 grams.