Why is dehydrated calcium chloride added during the extraction of sodium through electrolysis of sodium chloride ?
OR
Mention two ways of preventing the rusting of iron.
WBBSE
Class X
Physical Science
Metallurgy
02 Mark
2024
Dehydrated calcium chloride (CaCl2) is added during the electrolysis of sodium chloride (NaCl) because it lowers the melting point of sodium chloride. Sodium chloride has a high melting point, and adding CaCl2 helps to keep the electrolyte in a molten state at lower temperatures, making the process more efficient.
OR
Two ways of preventing the rusting of iron:
- Galvanization: Coating iron with a layer of zinc to protect it from exposure to moisture and air.
- Paint coating: Applying a layer of paint to prevent direct contact between iron and the environment.
Related Questions
More WBBSE Moderate level questions
1/12
Q.
In the extraction of metal by the process of electrolysis at which electrode does the...
A.
The reaction occurs at the cathode during the process of electrolysis. This...
Q.
Why does a copper vessel turn green in open air?
A.
Copper reacts slowly with moist air containing oxygen, carbon dioxide and water...
Q.
In the extraction of aluminium by the process of electrolysis, the fused mixture used contains...
A.
d. pure alumina. Explanation: In the extraction of aluminium through electrolysis, the...
Q.
Match the right column with the left column: 2.11.1. Noble Gas (a) Cs2.11.2. Inver (b)...
A.
Left Column Right Column (1) Noble Gas (b) Rn (2) Inver (d)...
Q.
The metal which is extracted through thermal reduction is
A.
(c) Fe Explanation Iron (Fe) is extracted by thermal reduction (reduction of...
Q.
Write two reasons why curd and sour fruits are not kept in copper and brass...
A.
Curd and sour fruits contain acids. Therefore, they should not be kept...
Q.
2.11.1. An alkaline earth metal (a) Fe 2.11.2. The metal which is present in the...
A.
2.11.1 → (c) Ca 2.11.2 → (a) Fe 2.11.3 → (d) K...
Q.
Which of the following is the formula of zine blende, an ore of zinc?
A.
b. ZnS Explanation: Zinc blende is the chief ore of zinc, and...
Q.
What reaction occurs at the cathode in the electrolyte method of extraction of aluminium?
A.
At the cathode in the electrolyte method of aluminium extraction, aluminium ions...
Q.
Name the metal which is extracted in thermite process.
A.
Iron (Fe) Explanation The thermite process is used to extract or weld...
Q.
Which of the following elements is not present in Duralumin? (a) Al (b) Zn (c)...
A.
(b) Zn Explanation Duralumin is an alloy composed mainly of: Aluminium (Al)...
Q.
Match the Right Column with the Left Column : 2.2.1 Metal present in German silver
A.
Left Column Correct Match 2.2.1 Metal present in German silver (d) Ni...