JEE Challenger
More from d and f Block Elements

Properties and Reaction Products of Zinc Chemical Processes

Consider the following unbalanced chemical reactions: Zn+hot conc. H2SO4→G+R+X\text{Zn} + \text{hot conc. } \text{H}_2\text{SO}_4 \rightarrow \text{G} + \text{R} + \text{X} Zn+conc. NaOH→T+Q\text{Zn} + \text{conc. } \text{NaOH} \rightarrow \text{T} + \text{Q} G+H2S+NH4OH→Z (a precipitate)+X+Y\text{G} + \text{H}_2\text{S} + \text{NH}_4\text{OH} \rightarrow \text{Z (a precipitate)} + \text{X} + \text{Y} Identify the correct statement(s) among the given choices:

Options

A

Z has a dirty white colour

Correct
B

The oxidation state of Zn in T is +1

C

R is a V-shaped molecule

Correct
D

Bond order of Q is 1 in its ground state

Correct

Step-by-Step Solution

To determine the correct statement(s), we first identify all the chemical species in the given reaction sequences.


Step 1: Identifying the Chemical Species

  1. Reaction with hot concentrated H2SO4\text{H}_2\text{SO}_4: Zn+2H2SO4 (hot conc.)⟶ZnSO4+SO2+2H2O\text{Zn} + 2\text{H}_2\text{SO}_4 \,(\text{hot conc.}) \longrightarrow \text{ZnSO}_4 + \text{SO}_2 + 2\text{H}_2\text{O}

    • G=ZnSO4\text{G} = \text{ZnSO}_4
    • R=SO2\text{R} = \text{SO}_2
    • X=H2O\text{X} = \text{H}_2\text{O}
  2. Reaction with concentrated NaOH\text{NaOH}: Zn+2NaOH (conc.)⟶Na2ZnO2+H2\text{Zn} + 2\text{NaOH} \,(\text{conc.}) \longrightarrow \text{Na}_2\text{ZnO}_2 + \text{H}_2

    • T=Na2ZnO2(Sodium Zincate)\text{T} = \text{Na}_2\text{ZnO}_2 \quad (\text{Sodium Zincate})
    • Q=H2\text{Q} = \text{H}_2
  3. Precipitation Reaction: ZnSO4+H2S+2NH4OH⟶ZnS↓+(NH4)2SO4+2H2O\text{ZnSO}_4 + \text{H}_2\text{S} + 2\text{NH}_4\text{OH} \longrightarrow \text{ZnS}\downarrow + (\text{NH}_4)_2\text{SO}_4 + 2\text{H}_2\text{O}

    • Z=ZnS(Zinc Sulfide precipitate)\text{Z} = \text{ZnS} \quad (\text{Zinc Sulfide precipitate})
    • Y=(NH4)2SO4\text{Y} = (\text{NH}_4)_2\text{SO}_4

Step 2: Evaluation of Options

  • Option (A): "Z has a dirty white colour"
    Z\text{Z} is ZnS\text{ZnS} (Zinc Sulfide). It precipitates as a characteristic dirty white solid in alkaline media.
    A is CORRECT.\mathbf{A\text{ is CORRECT.}}

  • Option (B): "The oxidation state of Zn in T is +1"
    T\text{T} is sodium zincate, Na2ZnO2\text{Na}_2\text{ZnO}_2. Calculating the oxidation state of Zn\text{Zn} (xx): 2(+1)+x+2(−2)=0  ⟹  x=+22(+1) + x + 2(-2) = 0 \implies x = +2 Thus, the oxidation state of Zn\text{Zn} in T\text{T} is +2+2.
    B is INCORRECT.\mathbf{B\text{ is INCORRECT.}}

  • Option (C): "R is a V-shaped molecule"
    R\text{R} is sulfur dioxide (SO2\text{SO}_2). The central sulfur atom undergoes sp2sp^2 hybridization, containing two bonding pairs and one lone pair of electrons. This steric arrangement results in a V-shaped (bent/angular) molecular geometry with a bond angle of approximately 119∘119^\circ.
    C is CORRECT.\mathbf{C\text{ is CORRECT.}}

  • Option (D): "Bond order of Q is 1 in its ground state"
    Q\text{Q} is dihydrogen gas (H2\text{H}_2). According to Molecular Orbital Theory, its ground-state electronic configuration is (σ1s)2(\sigma_{1s})^2.
    Bond Order=Nb−Na2=2−02=1\text{Bond Order} = \frac{N_b - N_a}{2} = \frac{2 - 0}{2} = 1
    D is CORRECT.\mathbf{D\text{ is CORRECT.}}


Conclusion

The correct options are A, C, and D.