Question

Explain how dalton’s atomic theory offered a convincing explanation of the observation that mass is conserved in chemical reactions

Answer 1

Dalton's atomic theory was based on the law of conservation of mass which states that the matter can neither be created nor be destroyed but it can only transformed into one form or another. In a chemical reaction, total mass of the reactants will be equal to the total mass of the products.

Taking an example,

$methane+oxygen\rightarrow \text{carbon dioxide}+water$

$CH_4+2O_2\rightarrow CO_2+2H_2O$

Mass of $CH_4$ = 16g

Mass of $2O_2$ = $2\times 32g$

Total mass on reactant side = $(16+2\times 32)$

Total mass on reactant side = 80g

Mass of $CO_2$ = 44g

Mass of $2H_2O=2\times 18g$

Total mass on product side = $(44+2\times 18)$

Total mass on product side = 80g

It is seen from the above example that the

total mass on reactant side = total mass on product side.