SATHEE: Qualitative Analysis - Result Question 50

Qualitative Analysis - Result Question 50

####53. When a white crystalline compound $X$ is heated with $K_{2} C r_{2} O_{7}$ and concentrated $H_{2} S O_{4}$ , a reddish brown gas $A$ is evolved. On passing $A$ into caustic soda solution, a yellow coloured solution $B$ is obtained. Neutralising the solution of $B$ with acetic acid and on subsequent addition of lead acetate a yellow precipitate $C$ is obtained.

When $X$ is heated with $N a O H$ solution, colourless gas is evolved and on passing this gas into $K_{2} H g I_{4}$ solution, a reddish brown precipitate $D$ is formed. Identify $A, B, C, D$ and $X$ . Write the equations of reactions involved.

(2002)

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Solution:

$X = N H_{4} C l; A = C r O_{2} C l_{2}; B = N a_{2} C r O_{4}; C = P b C r O_{4}$ ;

$D = H_{2} N (H g O) H g I$ .

Reactions involved :

(i) $4 N H_{4} C l (X) + K_{2} C r_{2} O_{7} + 6 H_{2} S O_{4} ⟶ 2 C r O_{2} C l_{2} (A) + 4 N H_{4} H S O_{4} + 2 K H S O_{4} + 3 H_{2} O$

(ii) $C r O_{2} C l_{2} (A) + 2 N a O H ⟶ N a_{2} C r O_{4} (B) + 2 H C l$

(iii) $N a_{2} C r O_{4} (B) + {(C H_{3} C O O)}_{2} P b ⟶ P b C r O_{4} ↓ (C) + 2 C H_{3} C O O N a$

(iv) $N H_{4} C l (X) + N a O H ⟶ N a C l + H_{2} O + N H_{3}$

(v) $2 K_{2} H g I_{4} + N H_{3} + 3 K O H ⟶ H_{2} N (H g O) H g I (D) + 7 K I + 2 H_{2} O$

Qualitative Analysis - Result Question 50

Solution:

Engineering Preparation

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Qualitative Analysis - Result Question 50

Solution:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

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