Question

The chemical equation ${\mathrm{N}}_2{\mathrm{O}}_5+{\mathrm{H}}_2\mathrm{O}\to {\mathrm{HNO}}_3$ in balanced form will be

• A. ${\mathrm{N}}_2{\mathrm{O}}_5+2{\mathrm{H}}_2\mathrm{O}\to 2{\mathrm{HNO}}_3$
• B. $2{\mathrm{N}}_2{\mathrm{O}}_5+{\mathrm{H}}_2\mathrm{O}\to 2{\mathrm{HNO}}_3$
• C. ${\mathrm{N}}_2{\mathrm{O}}_5+{\mathrm{H}}_2\mathrm{O}\to 2{\mathrm{HNO}}_3$

Answer 1

The correct option is C

${\mathrm{N}}_2{\mathrm{O}}_5+{\mathrm{H}}_2\mathrm{O}\to 2{\mathrm{HNO}}_3$

The explanation for Correct answer

(c) ${\mathrm{N}}_2{\mathrm{O}}_5+{\mathrm{H}}_2\mathrm{O}\to {\mathrm{HNO}}_3$

Step 1: Count the number of atoms of each element on both the sides

Number of atoms of each element on LHS,

Nitrogen(N) = 2 atoms , Oxygen(O) = 6 atoms, Hydrogen(H) = 2 atoms

Number of atoms of each element on RHS,

Nitrogen = 1 atom, Hydrogen = 1 atom, Oxygen = 3 atoms

We can see that there is an extra atom of nitrogen, hydrogen, and oxygen in LHS.

Step 2:

Multiply the product side by 2

${\mathrm{N}}_2{\mathrm{O}}_5+{\mathrm{H}}_2\mathrm{O}\to 2{\mathrm{HNO}}_3$

• Now on LHS, we have Nitrogen = 2 atoms, Hydrogen = 2 atoms, Oxygen = 6 atoms
• On RHS, we have Nitrogen(N) = 2 atoms , Oxygen(O) = 6 atoms, Hydrogen(H) = 2 atoms

Now, the number of atoms of each element is the same on both sides and, the equation is said to be balanced.

Therefore, the balanced chemical equation is ${\mathrm{N}}_2{\mathrm{O}}_5+{\mathrm{H}}_2\mathrm{O}\to 2{\mathrm{HNO}}_3$

The explanation for incorrect answer

(a) ${\mathrm{N}}_2{\mathrm{O}}_5+2{\mathrm{H}}_2\mathrm{O}\to 2{\mathrm{HNO}}_3$

• On LHS, we have Nitrogen = 2 atoms, Oxygen = 6 atoms, Hydrogen = 4 atoms
• On RHS, we have Nitrogen = 2 atoms, Oxygen = 6 atoms, Hydrogen = 2 atoms

The number of atoms in LHS is not equal to the number of atoms in RHS.

(b) $2{\mathrm{N}}_2{\mathrm{O}}_5+{\mathrm{H}}_2\mathrm{O}\to 2{\mathrm{HNO}}_3$

• On LHS, we have Nitrogen = 4 atoms, Oxygen = 11 atoms, Hydrogen = 2 atoms
• On RHS, we have Nitrogen = 2 atoms, Oxygen = 6 atoms, Hydrogen = 2 atoms

The number of atoms in LHS is not equal to the number of atoms in RHS.