Question

Complete and balance the following equations:
- NaCl + conc.{H_2}S{O_4}\xrightarrow{{ < {{200}^0}C}}\\_\\_\\_\\_\\_\\_ + \\_\\_\\_\\_\\_\\_
- NaN{O_3} + conc.{H_2}S{O_4}\xrightarrow{{ < {{200}^0}C}}\\_\\_\\_\\_\\_\\_ + \\_\\_\\_\\_\\_\\_
- N{a_2}C{O_3} + {H_2}S{O_4} \to \\_\\_\\_\\_\\_ + {H_2}O + \\_\\_\\_\\_\\_\left( g \right)
- NaHC{O_3} + {H_2}S{O_4} \to \\_\\_\\_\\_\\_ + {H_2}O + \\_\\_\\_\\_\\_\left( g \right)
- N{a_2}S{O_3} + HCl \to \\_\\_\\_\\_\\_ + {H_2}O + \\_\\_\\_\\_\\_\left( g \right)
- NaHS{O_3} + HCl \to \\_\\_\\_\\_\\_ + {H_2}O + \\_\\_\\_\\_\\_\left( g \right)
- Zn + HCl \to \\_\\_\\_\\_\\_ + \\_\\_\\_\\_\\_\left( g \right)

Answer 1

Hint : In order to complete a reaction, we need to first determine what is the type of the given reaction. The different types of reaction are decomposition reaction, composition reaction, combustion reaction, double displacement reaction and single displacement reaction. After completing the reaction, we need to balance the equation.

Complete Step By Step Answer:
- NaCl + conc.{H_2}S{O_4}\xrightarrow{{ < {{200}^0}C}}\\_\\_\\_\\_\\_\\_ + \\_\\_\\_\\_\\_\\_
This reaction is a double displacement reaction. Here sodium chloride is a reaction with concentrated sulphuric acid to give hydrogen chloride and sodium bisulphate. The reaction generally takes place at a temperature of $30 - 50^\circ C$ . Also, this reaction is one of the methods for the preparation of hydrogen chloride.
So, the correctly balanced and complete equation will be: -
- $NaCl + conc.{H_2}S{O_4}\xrightarrow{{ < {{200}^0}C}}NaHS{O_4} + HCl$
NaN{O_3} + conc.{H_2}S{O_4}\xrightarrow{{ < {{200}^0}C}}\\_\\_\\_\\_\\_\\_ + \\_\\_\\_\\_\\_\\_
This reaction is also a double displacement reaction. This reaction is used as a method for the preparation of the nitric acid. The products that will be formed in this reaction are sodium bisulphate and nitric acid. This reaction is also used as a confirmatory test for the salts of nitrate in salt analysis.
So, the correctly balanced and complete equation will be: -
- $NaN{O_3} + conc.{H_2}S{O_4}\xrightarrow{{ < {{200}^0}C}}NaHS{O_4} + HN{O_3}$
N{a_2}C{O_3} + {H_2}S{O_4} \to \\_\\_\\_\\_\\_ + {H_2}O + \\_\\_\\_\\_\\_\left( g \right)
This reaction is a double displacement reaction. Here we see that an acid and a base is a reaction to form salt and water therefore this reaction is also termed as the neutralization reaction. It is clear by looking at the reaction that a gas will be evolved and as the base we have is of carbonate so carbon dioxide will be evolved. The products formed in this reaction are sodium sulphate, water and carbon dioxide.
So, the correctly balanced and complete equation will be: -
- $N{a_2}C{O_3} + {H_2}S{O_4} \to N{a_2}S{O_4} + {H_2}O + C{O_2}\left( g \right)$
NaHC{O_3} + {H_2}S{O_4} \to \\_\\_\\_\\_\\_ + {H_2}O + \\_\\_\\_\\_\\_\left( g \right)
The given reaction is an example of the double displacement reaction. Here again we see that an acid and a base react to form salt and water, so this reaction will be termed as a neutralization reaction. The salt which is formed here is the salt of sulphate as the acid used in the reaction is the sulphuric acid. And it is already given in the reaction that a gas will be evolved. So, the products formed are sodium sulphate salt and water. Carbon dioxide gas is evolved in this reaction.
So, the correctly balanced and complete equation will be: -
- $2NaHC{O_3} + {H_2}S{O_4} \to N{a_2}S{O_4} + 2{H_2}O + 2C{O_2}$
N{a_2}S{O_3} + HCl \to \\_\\_\\_\\_\\_ + {H_2}O + \\_\\_\\_\\_\\_\left( g \right)
This reaction is also an example of double displacement reaction and neutralization reaction. This reaction is used as a method for the preparation of Sulphur dioxide gas as it is given in the reaction that a gas will be formed and the given base is of a sulphate so Sulphur dioxide is formed. So, the products of this reaction are sodium chloride, water and Sulphur dioxide.
Thus, the correctly balanced and complete equation will be: -
- $N{a_2}S{O_3} + 2HCl \to 2NaCl + {H_2}O + S{O_2}\left( g \right)$
NaHS{O_3} + HCl \to \\_\\_\\_\\_\\_ + {H_2}O + \\_\\_\\_\\_\\_\left( g \right)
This reaction is the same as it is also a neutralization and double displacement reaction. Also, this is used to prepare Sulphur dioxide the products formed are sodium chloride, water and Sulphur dioxide.
So, the correctly balanced and complete equation is: -
- $NaHS{O_3} + HCl \to Nacl + {H_2}O + S{O_2}\left( g \right)$
Zn + HCl \to \\_\\_\\_\\_\\_ + \\_\\_\\_\\_\\_\left( g \right)
The above reaction is completely different from the others as it is an example of the combination reaction. Here we see that zinc is reacting with hydrochloric acid to form zinc chloride and hydrogen gas. When zinc will react with hydrochloric acid, the reaction will bubble vigorously because hydrogen gas will be evolved.
Thus, the correctly balanced and complete equation will be: -
$Zn + 2HCl \to ZnC{l_2} + {H_2}\left( g \right)$

Note :
$NaN{O_3} + conc.{H_2}S{O_4}\xrightarrow{{ < {{200}^0}C}}NaHS{O_4} + HN{O_3}$ in this reaction after the formation of nitric acid, the nitric acid will further react with copper metal to form the nitrogen dioxide gas. The nitrogen dioxide gas will give off reddish brown fumes. Also, in the above reactions $N{a_2}C{O_3}$ used is a weak base.