Question

In a reaction, 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium ethanoate. Show that these observations are in agreement with law of conservation of mass.

Answer 1

Hint: It is known to us that matter can neither be created nor can it be destroyed but can only change from one form of matter to another form of matter.

Complete step by step solution:
We know that the law of conservation of mass states that in an isolated system the total mass of reactants should be equal to the total mass of products in all physical and chemical changes.
Now from question we can say that the reaction which takes place is: $N{a_2}C{O_3} + C{H_3}COOH \to C{O_2} + {H_2}O + C{H_3}COONa$.
Calculation:
Given, Mass of sodium carbonate ($N{a_2}C{O_3}$) = 5.3 g.
Mass of ethanoic acid ($C{H_3}COOH$)= 6 g.
So, total mass of reactants ($N{a_2}C{O_3} + C{H_3}COOH) = 5.3 + 6 = 11.3g$.
Also given, Mass of carbon dioxide produced ($C{O_2}$) = 2.2 g.
Mass of water produced in reaction (${H_2}O$) = 0.9 g.
Mass of sodium ethanoate ($C{H_3}COONa$)= 8.2 g.
So, total mass of products ($C{O_2} + {H_2}O + C{H_3}COONa) = 2.2 + 0.9 + 8.2 = 11.4g$.
Since, from above calculation we can say that the total mass of reactant is equal to the total mass of products and also there is no increase and decrease in total mass of matter during the physical and chemical change. Therefore, it can be concluded that the reaction:$N{a_2}C{O_3} + C{H_3}COOH \to C{O_2} + {H_2}O + C{H_3}COONa$ with observations given in question obeys the law of conservation of mass.

Note: It should be remembered that both mass and energy are interconvertible but the total mass and energy during any physical or chemical change remains constant.
Also, we should know that the law of conservation of mass was given by ‘Antoine Lavoisier’.