Question

Which of the following shows the balanced equation for the reaction that represents the decomposition of magnesium chlorate (Mg(ClO3)2)?
2Mg(ClO3)2 yields 2MgCl2 + 3O2
Mg(ClO3)2 yields MgCl2 + 3O2
2MgCl2 + 3O2 yields 2Mg(ClO3)2
MgCl2 + 3O2 yields Mg(ClO3)2

Answer 1

Answer:

Mg(ClO₃)₂ ⟶ MgCl₂ + 3O₂

Explanation:

The reaction gives magnesium chloride and oxygen.

The balanced equation is then

Mg(ClO₃)₂ ⟶ MgCl₂ + 3O₂

A is wrong, because it is not balanced (12 O atoms on left and 6 O atoms on right).

C and D are wrong because they have the reactants as products and vice versa.

Answer 2

Answer: $Mg(ClO3)2\rightarrow MgCl_2+3O_2$

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

Decomposition is a type of chemical reaction in which one reactant gives two or more than two products.

$A\rightarrow B+C$

Thus the balanced equation for decomposition of magnesium chlorate will be :

$Mg(ClO3)2\rightarrow MgCl_2+3O_2$