Question

Complete and balance the equation for the following acid-base neutralization reaction. If water is used as a solvent, write the reactants and products as aqueous ions. In some cases, there may be more than one correct answer, depending on the amount of reactants used.
(a)Mg(OH)2 + HClO4?
(b)SO3 + H2O? (Assume an excess of water and that the product dissolves)
(c) SrO + H2SO4?

Answer 1

Explanation:

A balanced equation is defined as the one that has equal number of atoms of all the elements present on both reactant and product side.

(a) $Mg(OH)_{2} + HClO_{4} \rightarrow Mg(ClO_{4})_{2} + H_{2}O$

Number of atoms on reactant side are as follows.

Mg = 1

O = 6

H = 3

Cl = 1

Number of atoms on product side are as follows.

Mg = 1

O = 9

H = 2

Cl = 2

So, to balance this equation we multiply $Mg(OH)_{2}$ by 2 on reactant side and multiply $H_{2}O$ by 2 on product side.

Therefore, the balanced reaction equation is as follows.

       $2Mg(OH)_{2} + HClO_{4} \rightarrow Mg(ClO_{4})_{2} + 2H_{2}O$  

(b)  $SO_{3} + H_{2}O \rightarrow H_{2}SO_{4}$

Number of atoms on reactant side are as follows.

S = 1

O = 4

H = 2

Number of atoms on product side are as follows.

S = 1

O = 4

H = 2

Therefore, this equation is balanced as it has same number of atoms on both reactant and product side.

(c)   $SrO + H_{2}SO_{4} \rightarrow SrSO_{4} + H_{2}O$

Number of atoms on  reactant side are as follows.

Sr = 1

O = 1

H = 2

S = 1

O = 4

Number of atoms on product side are as follows.

Sr = 1

O = 1

H = 2

S = 1

O = 4

Therefore, this equation is balanced.