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MODEL PAPER 2025 — Chemistry STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 ScienceChemistryMODEL PAPER 20253 Marks
Question
a. Write down the reaction occurring on two inert electrodes when electrolysis of copper chloride is done. What will happen if a concentrated solution of copper sulphate is replaced with copper chloride?
b. Write an expression for the molar conductivity of aluminium sulphate at infinite dilution according to Kohlrausch law.
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Answer

a) Product of electrolysis of Copper Chloride
Cathode(-)
Cu2+ + 2e ← Cu(s)
anode(+)
2CI → Cl2 + 2e
Product of electrolysis of concentrated Copper Sulphate
Anode(+) SO42S2O8 + 2e
Cathode (-) Cu2+ + 2e ← Cu(s)
(B) $\Lambda^0{ }_{\mathrm{m}}\left[\mathrm{Al}_2\left(\mathrm{SO}_4\right)_3\right]=2 \lambda^0{ }_{\mathrm{m}}\left(\mathrm{Al}^{3+}\right)+3 \lambda^0{ }_{\mathrm{m}}\left(\mathrm{SO}_4{ }^{2-}\right)$

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