Sodium hydroxide is NOT used for________.
preserving pickle
Understanding Sodium Hydroxide and its Uses
Sodium hydroxide ($\text{NaOH}$), also commonly known as caustic soda or lye, is a strong base and alkali metal hydroxide. It has many industrial applications due to its reactive nature. Let's examine the uses listed in the options to determine which one is NOT a use of sodium hydroxide.
Uses of Sodium Hydroxide Explained
Sodium Hydroxide in Soap Making
Sodium hydroxide is a key ingredient in the production of hard bar soap. The process is called saponification, where fats or oils react with a strong alkali like $\text{NaOH}$ to produce soap and glycerol. This is a fundamental chemical reaction in the soap industry.
Sodium Hydroxide in Newspaper/Paper Making
In the paper industry, especially for making paper from wood pulp (like newspapers), sodium hydroxide is used in the Kraft process. It helps to dissolve the lignin in the wood fibers, separating the cellulose which is then processed into paper. So, $\text{NaOH}$ plays a vital role in breaking down wood into pulp suitable for paper making.
Sodium Hydroxide in Degreasing Metals
Sodium hydroxide is a strong alkaline cleaner. Its ability to react with and dissolve fats, oils, and greases makes it highly effective for cleaning and degreasing metal surfaces. It's often used in industrial cleaning processes to prepare metals before plating, painting, or other treatments.
Sodium Hydroxide and Preserving Pickle
Pickles are preserved using methods that inhibit microbial growth, such as high salt concentration, acidity (vinegar), oil, or spices. Sodium hydroxide is a highly corrosive substance and a strong base. It is not suitable for consumption and would destroy the food rather than preserve it safely. Common food preservatives are acids, salts, sugars, or specific chemical compounds approved for food use, but never a strong base like $\text{NaOH}$.
Based on the analysis, sodium hydroxide is widely used in soap making, paper manufacturing, and degreasing metals, but it is NOT used for preserving pickle.
Revision Table: Sodium Hydroxide Applications
| Application | Is $\text{NaOH}$ Used? | Reason/Role of $\text{NaOH}$ |
|---|---|---|
| Making soap | Yes | Used in saponification (reaction with fats/oils) to form soap. |
| Making newspapers | Yes | Used in pulping wood (Kraft process) to dissolve lignin. |
| Degreasing metals | Yes | Strong alkaline cleaner that reacts with fats/oils. |
| Preserving pickle | No | Strong base, corrosive, and unsafe for food preservation; common methods use salt, acid, oil, etc. |
Additional Information on Sodium Hydroxide Properties and Uses
Sodium hydroxide is a versatile chemical with many other applications beyond those mentioned:
- Chemical Manufacturing: Used in the production of many chemicals, including plastics, textiles, and synthetic fibers.
- Petroleum Industry: Used in drilling muds and refining petroleum.
- Water Treatment: Used to adjust the pH of water and remove heavy metals.
- Drain Cleaner: A common component in drain cleaners due to its ability to hydrolyze fats and proteins (like hair).
It is crucial to handle sodium hydroxide with care as it is corrosive and can cause severe burns upon contact with skin or eyes.
Important Questions from Periodic Table
Which of the following is the most reactive metal?
Which of the following acids is injected into the skin during an ant bite?
Which of the following statements about carbon monoxide is INCORRECT?
Which of the following minerals does NOT fall in the category of non-metallic minerals?
Name the chemist who proved that the atomic number of an element is a more fundamental property than its atomic mass, which led to modification in Mendeleev's Periodic Law table?
