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- Practical Chemistry
NEET · Chemistry · Practical Chemistry
Given below are two statements: one is labelled as Assertion (A)...
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): When dilute is added to a solid nitrite salt, the gas evolved is initially colourless inside the liquid but turns into reddish-brown fumes at the mouth of the test tube.
Reason (R): Nitrite reacts with dilute acid to yield colourless nitrous oxide () gas, which is rapidly oxidized by atmospheric oxygen to form brown nitrogen dioxide ().
In the light of the above statements, choose the most appropriate answer from the options given below:
Assertion (A): When dilute is added to a solid nitrite salt, the gas evolved is initially colourless inside the liquid but turns into reddish-brown fumes at the mouth of the test tube.
Reason (R): Nitrite reacts with dilute acid to yield colourless nitrous oxide () gas, which is rapidly oxidized by atmospheric oxygen to form brown nitrogen dioxide ().
In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- ABoth (A) and (R) are true and (R) is the correct explanation of (A)
- BBoth (A) and (R) are true but (R) is not the correct explanation of (A)
- C(A) is true but (R) is false
- D(A) is false but (R) is true
Correct answer
C. (A) is true but (R) is false
Step-by-step solution
The assertion is a true factual observation from qualitative analysis. When dilute is added to a nitrite salt, a colourless gas is initially evolved which turns brown at the mouth of the test tube.
The reason is false. Nitrite reacts with dilute acid to yield nitric oxide (), not nitrous oxide (). is a colourless gas that is rapidly oxidized by atmospheric oxygen to form brown nitrogen dioxide (). The reactions are:
(brown fumes).
Therefore, (A) is true but (R) is false.
Answer: (A) is true but (R) is false
The reason is false. Nitrite reacts with dilute acid to yield nitric oxide (), not nitrous oxide (). is a colourless gas that is rapidly oxidized by atmospheric oxygen to form brown nitrogen dioxide (). The reactions are:
(brown fumes).
Therefore, (A) is true but (R) is false.
Answer: (A) is true but (R) is false