Question

If mixture of ammonium chloride and calcium hydroxide is heated in a test tube, which of the following will be detectable by a student?
(A) The odour of ammonia
(B) Odour of rotten eggs
(C) None of these
(D) Nitric acid fumes

Answer 1

Hint: To solve this, firstly write down the reaction when calcium hydroxide is heated with ammonium chloride. We get calcium chloride as one of the products along with 2 other products. One of them is responsible for a peculiar odour which can be detectable by a student.

complete step by step answer:
To answer this, we have to see the products formed when we heat ammonium chloride and calcium hydroxide.
According to the products formed we can identify how it will be detectable by a student.
We know that aluminium chloride is an inorganic compound with the chemical formula $N{{H}_{4}}Cl$. Ammonium chloride solution is slightly acidic in nature. And we know that calcium hydroxide is an inorganic compound with the formula $Ca{{\left( OH \right)}_{2}}$ and it is alkaline in nature.
Now let us see the reaction of calcium hydroxide and ammonium chloride:
\[2N{{H}_{4}}Cl+Ca{{\left( OH \right)}_{2}}\to 2N{{H}_{3}}+2{{H}_{2}}O+CaC{{l}_{2}}\]
We can see that 1 mole of ammonium chloride reacts with one mole of calcium hydroxide and gives us 2 moles of ammonia and 2 moles of water along with one mole of calcium chloride as a product.
We can see that ammonia is produced during the reaction. Therefore, there will be an odour of ammonia which can be detectable by a student.

Therefore, the correct answer is option (A) the odour of ammonia.

Note: We get the odour of rotten eggs from hydrogen sulphide gas. Hydrogen sulphide gas is a natural product of decay and is most commonly a result of decomposition in sewage systems or in septic. Nitric acid is a strong oxidizing agent and highly corrosive in nature. Nitric acid fumes might cause immediate irritation of the respiratory tract and also pain and dyspnea. Ammonia has a strong pungent smell. It has a very strong irritating odour.