Question

Balance the following chemical equations including the physical state.
a) ${C_6}{H_{12}}{O_6} \to {C_2}{H_5}OH + C{O_2}$
b) $Fe + {O_2} \to F{e_2}{O_3}$
c) $N{H_3} + C{l_2} \to {N_2} + N{H_4}Cl$
d) $Na + {H_2}O \to NaOH + {H_2}$

Answer 1

Hint:A balanced chemical equation means that there must be equal numbers of atoms for each element involved in the reaction on the reactant and product sides. Physical states determine in which form reactant is used and in which state product is formed. These two things are necessary to represent a chemical equation.

Complete answer:
Law of conservation of mass:
This law states that the total mass of the reactant is equal to the total mass of the product. There is no gain of loss in the mass during the reaction. Every chemical equation must satisfy this law to be a balanced chemical equation.
a) ${C_6}{H_{12}}{O_6} \to {C_2}{H_5}OH + C{O_2}$
This reaction is alcoholic fermentation of glucose. By using the law of conservation of mass the balanced equation will be:
\[\;\] ${C_6}{H_{12}}{O_6}_{(aq)} \to 2{C_2}{H_5}O{H_{(aq)}} + 2C{O_2}_{(aq)}$
b) $Fe + {O_2} \to F{e_2}{O_3}$
In this reaction iron reacts with oxygen to form iron oxide. By using the law of conservation of mass the balanced equation will be:
$4F{e_{(s)}} + 3{O_{2(g)}} \to 2F{e_2}{O_{3(s)}}$
c) $N{H_3} + C{l_2} \to {N_2} + N{H_4}Cl$
In this reaction ammonia molecule reacts with chlorine molecule to form nitrogen gas and ammonium chloride. By using the law of conservation of mass the balanced equation will be:
$8N{H_{3(l)}} + 3C{l_{2(g)}} \to {N_{2(g)}} + 6N{H_4}C{l_{(s)}}$
d) $Na + {H_2}O \to NaOH + {H_2}$
In this reaction sodium reacts with water molecules to form sodium hydroxide and hydrogen gas. By using the law of conservation of mass the balanced equation will be:
$2N{a_{(s)}} + 2{H_2}{O_{(l)}} \to 2NaO{H_{(s)}} + {H_{2(g)}}$

Note:
Simply, we can confirm that reaction is balanced or not by adding the number of atoms of each element on the reactant side and similarly add the number of atoms of each element on the product side. If they are equal then the chemical equation is balanced.