Question

Write a balanced equation for reaction between sodium nitrate and concentrated sulphuric acid.
A. \[NaN{O_3} + 2{H_2}S{O_4} \to 2N{a_2}S{0_4} + 4HN{O_3}\]
B. \[4NaN{O_3} + {H_2}S{O_4} \to 2N{a_2}S{0_4} + 2HN{O_3}\]
C. \[2NaN{O_3} + {H_2}S{O_4} \to N{a_2}S{0_4} + 2HN{O_3}\]
D. \[NaN{O_3} + {H_2}S{O_4} \to N{a_2}S{0_4} + 2HN{O_3}\]

Answer 1

Hint: In a balanced chemical reaction the number of all atoms are equal in both sides. A reaction can be replacement reaction, redox reaction etc. In a replacement reaction the oxidation number of each atom remains the same only groups (positive ion or negative ions ) are interchanged with each other. But in redox change of oxidation state happens.

Complete step by step solution:
To balance a reaction at first you need to know if it is a redox reaction of a replacement reaction. The reaction between sodium nitrate and concentrated sulphuric acid is a replacement reaction. In this reaction oxidation state of each atom remains the same at before and after the reaction.
Therefore, to balance this reaction you need to make the number of atoms of both sides equal. And write down the balanced reaction of sodium nitrate and concentrated sulphuric acid as follows,
\[2NaN{O_3} + {H_2}S{O_4} \to N{a_2}S{0_4} + 2HN{O_3}\]
Here in this reaction numbers of the oxygen, nitrogen, sodium, hydrogen, sulfur are the same on both sides.

Therefore, the correct option is C.

Note: In this reaction nitric acid and sodium sulfate is formed. Here nitric acid is a weaker acid than sulfuric acid . Due to this reason nitric acid can be formed from its salt using sulfuric acids. Strong acids can produce weak acids from their salts.