Question

Brine is an :

• A. Aqueous solution of sodium hydroxide.
• B. Aqueous solution of sodium carbonate.
• C. Aqueous solution of sodium chloride.
• D. Aqueous solution of sodium bicarbonate.

Hint:

In the Chlor-Alkali process, the electrolysis of "concentrated brine" (\(NaCl\) solution) produces three highly useful industrial chemicals: Chlorine gas, Hydrogen gas, and Caustic Soda (\(NaOH\)).

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks for the chemical definition of the term "brine," which is widely used in industrial chemical processes.

Step 2: Key Formula or Approach:
Identify the specific salt dissolved in water to make brine. Brine is a high-concentration aqueous solution of common salt.

Step 3: Detailed Explanation:

• Brine is a common industrial term for a highly concentrated solution of sodium chloride (\(NaCl\)) in water.

• Typically, the salt concentration in brine ranges from \(3\%\) to \(26\%\) (saturated solution) by weight, depending on its industrial application.

• Brine is a crucial raw material in the chemical industry, particularly in the Chlor-Alkali process.

• During the electrolysis of brine, chlorine gas, hydrogen gas, and sodium hydroxide are manufactured on a large scale:
\[ 2NaCl\text{(aq)} + 2H_2O\text{(l)} \xrightarrow{\text{Electrolysis}} 2NaOH\text{(aq)} + Cl_2\text{(g)}\uparrow + H_2\text{(g)}\uparrow \] - This reaction makes brine highly valuable in the manufacturing of soaps, detergents, paper, and bleaching powder.

• It is also used as a preservative in the food industry and as a heat-transfer fluid in refrigeration systems due to its low freezing point.


Step 4: Final Answer:
Brine is an aqueous solution of sodium chloride.