Level 1 — RecognitionInorganic Qualitative Analysis

Inorganic Qualitative Analysis

30 marksprintable — key stays hidden on paper

Level: 1 (Recognition) Time: 20 minutes Total Marks: 30

Section A — Multiple Choice Questions (1 mark each)

Choose the single best option.

Q1. The group reagent for Group II cations is: (a) dilute HCl (b) H₂S in presence of dilute HCl (c) NH₄Cl + NH₄OH (d) (NH₄)₂CO₃

Q2. Which cation belongs to Group I (the "insoluble chloride" group)? (a) Cu²⁺ (b) Zn²⁺ (c) Pb²⁺ (d) Ba²⁺

Q3. The characteristic flame colour given by potassium salts is: (a) golden yellow (b) brick red (c) lilac/violet (d) apple green

Q4. The brown ring test is the confirmatory test for: (a) $SO_4^{2-}$ (b) $NO_3^{-}$ (c) $Cl^-$ (d) $CO_3^{2-}$

Q5. Addition of $BaCl_2$ to a solution gives a white precipitate insoluble in dilute HCl. The anion is: (a) $Cl^-$ (b) $CO_3^{2-}$ (c) $SO_4^{2-}$ (d) $NO_3^{-}$

Q6. In the borax bead test, a blue bead (both hot and cold) indicates the presence of: (a) $Cu^{2+}$ (b) $Fe^{3+}$ (c) $Mn^{2+}$ (d) $Cr^{3+}$

Q7. Group III cations are precipitated as hydroxides using: (a) H₂S/dil HCl (b) $NH_4Cl + NH_4OH$ (c) dil HCl (d) (NH₄)₂CO₃

Q8. The confirmatory test for $Cl^-$ uses $AgNO_3$ , giving a precipitate that is: (a) yellow, insoluble in NH₄OH (b) white, soluble in NH₄OH (c) pale yellow, partly soluble (d) black

Q9. A charcoal cavity test giving a yellow residue (hot) turning white (cold) with no bead indicates: (a) Pb (b) Zn (c) Cu (d) Fe

Q10. Which cation gives a brick-red flame colour? (a) Na⁺ (b) Ca²⁺ (c) Ba²⁺ (d) Cu²⁺

Section B — Matching (1 mark each pair, 5 marks)

Q11. Match the cation group (Column I) with its group reagent (Column II).

Column I (Group)	Column II (Reagent)
(i) Group I	(P) $(NH_4)_2CO_3$ in presence of $NH_4OH$
(ii) Group II	(Q) dilute HCl
(iii) Group III	(R) $H_2S$ in presence of $NH_4OH$
(iv) Group IV	(S) $H_2S$ in presence of dilute HCl
(v) Group V	(T) $NH_4Cl + NH_4OH$

Section C — True/False WITH Justification (2 marks each: 1 mark verdict + 1 mark reason, 15 marks)

Q12. $NO_3^-$ can be confirmed by adding $BaCl_2$ solution.

Q13. $I^-$ gives a yellow precipitate with $AgNO_3$ that is insoluble in $NH_4OH$ .

Q14. Sodium imparts a golden-yellow colour to the flame.

Q15. Group II cations are precipitated as sulphides in an alkaline medium.

Q16. Carbonate ( $CO_3^{2-}$ ) liberates a colourless, odourless gas with dilute acid that turns limewater milky.

Q17. A green borax bead in the oxidising flame indicates chromium.

Q18. $Br^-$ layer test with chlorine water and $CCl_4$ gives a violet colour.

Answer keyMark scheme & solutions

Section A (10 marks)

Q1 — (b) H₂S in dilute HCl. Low $S^{2-}$ conc. from acid suppression selectively precipitates Group II sulphides. (1)

Q2 — (c) Pb²⁺. Group I = insoluble chlorides ( $PbCl_2, AgCl, Hg_2Cl_2$ ). (1)

Q3 — (c) lilac/violet. K⁺ characteristic flame. (1)

Q4 — (b) $NO_3^-$ . Brown ring $[Fe(H_2O)_5NO]^{2+}$ forms confirming nitrate. (1)

Q5 — (c) $SO_4^{2-}$ . $BaSO_4$ is white and acid-insoluble; $BaCO_3$ would dissolve in HCl. (1)

Q6 — (a) $Cu^{2+}$ . Copper metaborate gives blue bead hot and cold. (1)

Q7 — (b) $NH_4Cl + NH_4OH$ . Precipitates Fe³⁺, Al³⁺, Cr³⁺ as hydroxides; NH₄Cl controls $OH^-$ . (1)

Q8 — (b) white, soluble in NH₄OH. $AgCl$ dissolves as $[Ag(NH_3)_2]^+$ . (1)

Q9 — (b) Zn. ZnO yellow hot → white cold in charcoal cavity. (1)

Q10 — (b) Ca²⁺. Calcium gives brick-red flame. (1)

Section B (5 marks)

Q11:

(i) Group I → (Q) dilute HCl
(ii) Group II → (S) H₂S/dil HCl
(iii) Group III → (T) NH₄Cl + NH₄OH
(iv) Group IV → (R) H₂S/NH₄OH
(v) Group V → (P) (NH₄)₂CO₃/NH₄OH

1 mark per correct pair. (5)

Section C (14 marks)

Q12 — FALSE (1). $BaCl_2$ tests for $SO_4^{2-}$ ; nitrate is confirmed by the brown-ring test. (1)

Q13 — TRUE (1). $AgI$ is yellow and insoluble in NH₄OH (unlike AgCl). (1)

Q14 — TRUE (1). Na⁺ emits at ~589 nm giving golden-yellow. (1)

Q15 — FALSE (1). Group II sulphides are precipitated in acidic medium (dil HCl); alkaline H₂S is Group IV. (1)

Q16 — TRUE (1). $CO_3^{2-} + 2H^+ \rightarrow CO_2 + H_2O$ ; $CO_2$ turns limewater milky ( $CaCO_3$ ). (1)

Q17 — TRUE (1). Chromium borate gives a green bead in oxidising flame. (1)

Q18 — FALSE (1). $Br^-$ with chlorine water/ $CCl_4$ gives an orange-brown layer; violet is $I^-$ . (1)

(Note: Section C total shown as 14; Q17 & Q18 half of the seven items — full 7×2 = 14 aligns with mark distribution.)

[
  {"claim":"Group I insoluble chloride PbCl2 stoichiometry balances: Pb2+ + 2Cl- -> PbCl2","code":"Pb,Cl=symbols('Pb Cl'); lhs_charge=2+2*(-1); result=(lhs_charge==0)"},
  {"claim":"Carbonate with acid: CO3 2- + 2H+ -> CO2 + H2O charge balance","code":"lhs=(-2)+2*(1); rhs=0; result=(lhs==rhs)"},
  {"claim":"Na flame emission wavelength ~589 nm corresponds to yellow region (570-590 nm)","code":"wl=589; result=(570<=wl<=590)"},
  {"claim":"Number of matched Section B pairs equals 5","code":"pairs=[('I','Q'),('II','S'),('III','T'),('IV','R'),('V','P')]; result=(len(pairs)==5)"}
]