Qualitative salt analysis — practice questions

Question 1 · difficulty L1 · recall

Which gas is evolved when an ammonium salt is warmed with aqueous sodium hydroxide?

• A. Ammonia
• B. Carbon dioxide
• C. Hydrogen chloride
• D. Sulphur dioxide

Question 2 · difficulty L2 · understanding

Given below are two statements : Statement (I) : Nitrogen, sulphur, halogen and phosphorus present in an organic compound are detected by Lassaigne's Test. Statement (II) : The elements present in the compound are converted from covalent form into ionic form by fusing the compound with Magnesium in Lassaigne's test. In the light of the above statements, choose the correct answer from the options given below :

• A. Both Statement I and Statement II are false
• B. Statement I is true but Statement II is false
• C. Statement I is false but Statement II is true
• D. Both Statement I and Statement II are true

Question 3 · difficulty L2 · understanding

A salt solution gives a white precipitate with barium chloride that remains insoluble in dilute hydrochloric acid. Which anion is indicated?

• A. Carbonate
• B. Sulphate
• C. Sulphite
• D. Nitrate

Question 4 · difficulty L2 · understanding

In the Group analysis of cations, $\mathrm{Ba}^{2+}$ & $\mathrm{Ca}^{2+}$ are precipitated respectively as

• A. sulphide & sulphide
• B. hydroxide & carbonate
• C. chromate & sulphide
• D. carbonate & carbonate

Question 5 · difficulty L2 · understanding

When a salt is treated with sodium hydroxide solution it gives gas X . On passing gas X through reagent Y a brown coloured precipitate is formed. X and Y respectively, are

• A. $\mathrm{X}=\mathrm{NH}_3$ and $\mathrm{Y}=\mathrm{HgO}$
• B. $\mathrm{X}=\mathrm{NH}_4 \mathrm{Cl}$ and $\mathrm{Y}=\mathrm{KOH}$
• C. $\mathrm{X}=\mathrm{NH}_3$ and $\mathrm{Y}=\mathrm{K}_2 \mathrm{HgI}_4+\mathrm{KOH}$
• D. $\mathrm{X}=\mathrm{HCl}$ and $\mathrm{Y}=\mathrm{NH}_4 \mathrm{Cl}$

Question 6 · difficulty L2 · understanding

Formation of $\mathrm{Na}_4\left[\mathrm{Fe}(\mathrm{CN})_5 \mathrm{NOS}\right]$, a purple coloured complex formed by addition of sodium nitroprusside in sodium carbonate extract of salt indicates the presence of :

• A. Sulphide ion
• B. Sulphite ion
• C. Sulphate ion
• D. Sodium ion

Question 7 · difficulty L2 · understanding

Identify A, B and C in the given below reaction sequence

• A. $\mathrm{PbCl}_2, \mathrm{PbSO}_4, \mathrm{PbCrO}_4$
• B. $\mathrm{PbS}, \mathrm{PbSO}_4, \mathrm{~Pb}\left(\mathrm{CH}_3 \mathrm{COO}\right)_2$
• C. $\mathrm{PbS}, \mathrm{PbSO}_4, \mathrm{PbCrO}_4$
• D. $\mathrm{PbCl}_2, \mathrm{~Pb}\left(\mathrm{SO}_4\right)_2, \mathrm{PbCrO}_4$

Question 8 · difficulty L2 · understanding

Match List I with List II LIST I (Name of the test) LIST II (Reaction sequence involved) [M is metal] A. Borax bead test I. $$\mathrm{MCO}_3 \rightarrow \mathrm{MO} \xrightarrow[+\Delta]{\mathrm{Co}\left(\mathrm{NO}_3\right)_2} \mathrm{CoO} \cdot \mathrm{MO}$$ B. Charcoal cavity test II. $$\mathrm{MCO}_3 \rightarrow \mathrm{MCl}_2 \rightarrow \mathrm{M}^{2+}$$ C. Cobalt nitrate test III. $$\mathrm{MSO}_4 \xrightarrow[\Delta]{\mathrm{Na}_2 \mathrm{~B}_4 \mathrm{O}_7} \mathrm{M}\left(\mathrm{BO}_2\right)_2 \rightarrow \mathrm{MBO}_2 \rightarrow \mathrm{M}$$ D. Flame test IV. $$\mathrm{MSO}_4 \xrightarrow[\Delta]{\mathrm{Na}_2 \mathrm{CO}_3} \mathrm{MCO}_3 \rightarrow \mathrm{MO} \rightarrow \mathrm{M}$$ Choose the correct answer from the options given below:

• A. A-III, B-I, C-IV, D-II
• B. A-III, B-IV, C-I, D-II
• C. A-III, B-II, C-IV, D-I
• D. A-III, B-I, C-II, D-IV

Question 9 · difficulty L2 · understanding

Given below are two statements : Statement (I) : The gas liberated on warming a salt with dil $$\mathrm{H}_2 \mathrm{SO}_4$$, turns a piece of paper dipped in lead acetate into black, it is a confirmatory test for sulphide ion. Statement (II) : In statement-I the colour of paper turns black because of formation of lead sulphite. In the light of the above statements, choose the most appropriate answer from the options given below :

• A. Both Statement I and Statement II are false
• B. Statement I is true but Statement II is false
• C. Both Statement I and Statement II are true
• D. Statement I is false but Statement II is true

Question 10 · difficulty L2 · understanding

In the wet tests for detection of various cations by precipitation, $$\mathrm{Ba}^{2+}$$ cations are detected by obtaining precipitate of

• A. $$\mathrm{BaSO}_{4}$$
• B. $$\mathrm{Ba}(\mathrm{OAc})_{2}$$
• C. $$\mathrm{BaCO}_{3}$$
• D. $$\mathrm{Ba}(\mathrm{ox})$$ : Barium oxalate