A series of experiments were performed as shown below to prepare certain gases in the laboratory.

(i) Name the gas A. What do you observe when gas A is passed through AgNO₃ solution ?

(ii) Name the gas B. What test will you perform to identify gas B.

(iii) What is the similarity between gas B and gas C ?

(iv) Give a test to distinguish between gases B and C.

(v) In experiment IV, gas D is :

P — HCl
Q — Cl₂
R — O₂

1. Only P
2. Only Q
3. Only R
4. Both P and Q

(vi) Write the equations for when gas B and gas C are separately passed in lime water first in little quantities and then in excess.

(vii) When a rod dipped in ammonium hydroxide solution is brought near gas …………… dense white fumes are seen.

P — Gas A
Q — Gas B
R — Gas D

1. Only P
2. Only Q
3. Only R
4. Both P and R

(i) Gas A is HCl, When the HCl is passed through silver nitrate solution, a white precipitate of silver chloride is formed.

AgNO₃ (aq) + HCl ⟶ AgCl ↓ + HNO₃

(ii) Gas B is SO₂ , it decolorises purplish pink acidified potassium permanganate solution.

(iii) Gas B is SO₂ and Gas C is CO₂, they are colourless, acidic gases which can turn lime water milky (turbid).

(iv) Gas B (SO₂) decolorises purplish pink acidified potassium permanganate solution and it can change orange/yellow solution of acidified potassium dichromate green. Gas C (CO₂) has no effect on acidified potassium permanganate solution and acidified potassium dichromate solution.

(v) Only Q,

MnO₂ + 4HCl ⟶ MnCl₂ + H₂O + Cl₂

(vi)

CO₂ in limited Quantity:

$\text{Ca(OH)}$2 + \text{CO}2 \longrightarrow \text{CaCO}3 \downarrow + \text{ H}2\text{O}

CO₂ passed in excess:

$\underset{\text{ppt}}{\text{CaCO}$3}+{\text{CO}2}+{\text{H}2{\text{O}}}\longrightarrow \underset{\text{soluble}}{{\text{Ca(HCO}3)_2}}

SO₂ in limited Quantity:

$\text{Ca(OH)}$2 + \text{SO}2 \longrightarrow \text{CaSO}3 \downarrow + \text{ H}2\text{O}

SO₂ passed in excess:

$\underset{\text{ppt}}{\text{CaSO}$3}+{\text{SO}2}+{\text{H}2{\text{O}}}\longrightarrow \underset{\text{soluble}}{{\text{Ca(HSO}3)_2}}

(vii) Only P

When a glass rod dipped in ammonia solution and brought near the gas A i.e., HCl, dense white fumes of ammonium chloride are formed.

NH₃ (aq) + HCl ⟶ NH₄Cl