Question

Which of the following is a balanced equation?

• A. ${\mathrm{H}}_2+3{\mathrm{O}}_2\to 4{\mathrm{H}}_2\mathrm{O}$
• B. $\mathrm{Fe}+3{\mathrm{O}}_2\to 2{\mathrm{Fe}}_2{\mathrm{O}}_3$
• C. $\mathrm{C}+2{\mathrm{O}}_2\to {\mathrm{CO}}_2$
• D. none of these

Answer 1

The correct option is D

none of these

Explanation for the correct option: (d) none of these.

Out of the 3 equations, none of these are balanced.

Explanation for the incorrect options: (a) ${\mathrm{H}}_2+3{\mathrm{O}}_2\to 4{\mathrm{H}}_2\mathrm{O}$

In this, neither oxygen nor hydrogen is balanced.

Elements	Number of atoms on the reactant side	Number of atoms on the product side
H	2	8
O	6	4

The balanced form will be: $2{\mathrm{H}}_2+{\mathrm{O}}_2\to 2{\mathrm{H}}_2\mathrm{O}$

(b) $\mathrm{Fe}+3{\mathrm{O}}_2\to 2{\mathrm{Fe}}_2{\mathrm{O}}_3$

In this, oxygen is balanced, but iron is not.

Elements	Number of atoms on the reactant side	Number of atoms on the product side
Fe	1	4
O	6	6

The balanced form will be: $4\mathrm{Fe}+3{\mathrm{O}}_2\to 2{\mathrm{Fe}}_2{\mathrm{O}}_3$

(c) $\mathrm{C}+2{\mathrm{O}}_2\to {\mathrm{CO}}_2$

In this, carbon is balanced, but oxygen is not.

Elements	Number of atoms on the reactant side	Number of atoms on the product side
C	1	1
O	4	2

The balanced form will be: $\mathrm{C}+{\mathrm{O}}_2\to {\mathrm{CO}}_2$

Hence, option (d) none of these is the correct answer.