What is the quantity of charge, in Faraday units, required for the reduction of 3.5 moles of $$\mathrm{Cr}_2 \mathrm{O} 7^{2-}$$ in acid medium?
A dry cell consists of a moist paste of $$\mathrm{NH}_4 \mathrm{Cl}$$ and $$\mathrm{ZnCl}_2$$ contained in a $$\mathrm{Zn}$$ casing which encloses a Carbon rod surrounded by black $$\mathrm{MnO}_2$$ paste. What is the role of $$\mathrm{ZnCl}_2$$ in it?
Compounds $$\mathrm{A}$$ and $$\mathrm{B}$$, having the same molecular formula $$(\mathrm{C}_4 \mathrm{H}_8 \mathrm{O})$$, react separately with $$\mathrm{CH}_3 \mathrm{MgBr}$$, followed by reaction with dil. $$\mathrm{HCl}$$ to form compounds $$\mathrm{X}$$ and $$\mathrm{Y}$$ respectively. Compound $$\mathrm{Y}$$ undergoes acidic dehydration in presence of Conc. $$\mathrm{H}_2 \mathrm{SO}_4$$ much more readily than $$\mathrm{X}$$. Compound $$\mathrm{Y}$$ also reacts with Lucas reagent, much more readily than $$\mathrm{X}$$, with appearance of turbidity. Identify $$\mathrm{X}$$ and $$\mathrm{Y}$$.
Match the names of reactions given in Column I with the appropriate reactions given in Column II.
No. | Name of reaction | No. | Equations representing reactions |
---|---|---|---|
(A) | Sandmeyer | (P) | $$ 2 \mathrm{C}_6 \mathrm{H}_5 \mathrm{Cl}+\mathrm{Na} \text { (dry ether) } \rightarrow \text { Diphenyl. } $$ |
(B) | Fittig | (Q) | $$ \mathrm{CH}_3-\mathrm{CHBr}-\mathrm{CH}_3+\mathrm{AgF} \rightarrow \mathrm{CH}_3-\mathrm{CHF}-\mathrm{CH}_3+\mathrm{AgBr} $$ |
(C) | Swarts | (R) | $$ \mathrm{CH}_3-\mathrm{CH}_2-\mathrm{Br}+\mathrm{Nal} \text { ( Acetone) } \rightarrow \mathrm{CH}_3-\mathrm{CH}_2-\mathrm{I}+\mathrm{NaBr} $$ |
(D) | Finkelstein | (S) | $$ \mathrm{C}_6 \mathrm{H}_5 \mathrm{~N}_2+\mathrm{Cl}-+\mathrm{Cu}_2 \mathrm{Br}_2 / \mathrm{HBr} \rightarrow \mathrm{C}_6 \mathrm{H}_5 \mathrm{Br}+\mathrm{N}_2 $$ |