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MODEL PAPER 2025 — Chemistry STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 ScienceChemistryMODEL PAPER 20255 Marks
Question
$(a).$ Using, Valence Bond Theory identify $\ce{A, B, C, D, E}$ and $\ce{F}$ in the following table$:$​​​​​​​
Image
$(b).$ Write the ionic equations for the reaction of acidified $\ce{K_2Cr_2O_7}$ with
$\ce{(i) H_2S}$ and $\ce{(ii) FeSO_4}​​​​​​​$​​​​​​​
✓

Answer

$(a).A = Co^{2+}$
$B = 3$
$C = d^2sp^3$
$D =$ Paramagnetic
$E = sp^3$
$F =$ tetrahedral
$\ce{(b). (i) Cr_2O_7^{2-} + 8 H^+ + 3 H_2S \rightarrow 2 Cr^{3+} + 3S + 7 H_2O}$
$\ce{(ii) Cr_2O_7^{2-} + 14 H^+ 6 Fe^{2+} 2 Cr^{3+} + 6 Fe^{3+} + 7 H_2O}$

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