Question

Which chemical equation best illustrates the Law of Conservation of Mass? (3 points) A. 2H2O yields H2 + O2 B. CH4 + 3O2yields CO2 + 2H2O C. Al4C3 + 3H2O yields CH4 + 4Al(OH)3 D. Zn + 2HCl yields ZnCl2 + H2

Answer 1

option d will illustrate the law of conservation Of mass

Answer 2

Answer: The correct answer is Option D.

Explanation:

Law of Conservation of mass states that the mass will remain constant for a balanced equation. This is carried out when the total number of atoms on reactant side is same as the total number of atoms on the product side.

For the given options:

Option A:

$2H_2O\rightarrow H_2+O_2$

The given equation is not balanced. So, the number of atoms are not equal on reactant as well as the product side. Hence, this equation will not follow law of conservation of mass.

Option B:

$CH_4+3O_2\rightarrow CO_2+2H_2O$

The given equation is not balanced. So, the number of atoms are not equal on reactant as well as the product side. Hence, this equation will not follow law of conservation of mass.

Option C:

$Al_4C_3+3H_2O\rightarrow CH_4+4Al(OH)_3$

The given equation is not balanced. So, the number of atoms are not equal on reactant as well as the product side. Hence, this equation will not follow law of conservation of mass.

Option D:

$Zn+2HCl\rightarrow ZnCl_2+H_2$

Total mass on the reactant side: $[65+2(1+35.5)]=138g/mol$

Total mass on the product side: $[(65+(2\times 35.5))+(2\times 1)]=138g/mol$

As, the total mass on reactant and product side is same. Hence, this equation will follow law of conservation of mass.

Therefore, the correct option is Option D.