The efficiency of a fuel cell is given by:

1. $\frac{∆H}{∆G}$

2. $\frac{∆G}{∆S}$

3. $\frac{∆G}{∆H}$

4. $\frac{∆S}{∆G}$

The compound on hydrolysis of 50% aqueous sodium hydroxide that produces the corresponding alcohol and acid is:

1. $C_6{H}_{5}C{H}_{2}CHO$

2. $C_6{H}_{5}CHO$

3. $C{H}_{3}C{H}_{2}C{H}_{2}CHO$

4. ${\mathrm{CH}}_3-\stackrel{\mathrm{O}}{\stackrel{\left|\right|}{\mathrm{C}}}-{\mathrm{CH}}_3$

Identify the correct order of the size of the following:

1. $C{a}^{2+}<K^{+}<Ar<S^{2-}<C{l}^{-}$

2. $C{a}^{2+}<K^{+}<Ar<C{l}^{-}<S^{2-}$

3. $Ar<C{a}^{2+}<K^{+}<C{l}^{-}<S^{2-}$

4. $C{a}^{2+}<A{r}^{+}<K^{+}<C{l}^{-}<S^{2-}$

Consider the following compounds:

(i)	C6H5COCl	(ii)
(iii)		(iv)

What is the correct decreasing order of their reactivity towards hydrolysis?

1. (ii) > (iv) > (iii) > (i)

2. (i) > (ii) > (iii) > (iv)

3. (iv) > (ii) > (i) > (iii)

4. (ii) > (iv) > (i) > (iii)

The product formed in aldol condensation is:

If NaCl is doped with 10^-4mol% of SrCl₂, the concentration of cation vacancies will be (N_A= 6.02×10²³mol^-1):

1. $6.02\times {10}^{15}$ $mo{l}^{-1}$

2. $6.02\times {10}^{16}$ $mo{l}^{-1}$

3. $6.02\times {10}^{17}$ $mo{l}^{-1}$

4. $6.02\times {10}^{14}$ $mo{l}^{-1}$

The d-electron configurations of Cr²⁺, Mn²⁺, Fe²⁺ and Ni²⁺ and 3d⁴, 3d⁵, 3d⁶ and 3d⁸ respectively.
Which one of the following aqua complexes will exhibit the minimum paramagnetic behaviour? 
(At. No. Cr = 24, Mn = 25, Fe = 26, Ni = 28)

1. \(\left[\mathrm{Mn}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\)
2. \(\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\)
3. \(\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\)
4. \(\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}\)

The order of decreasing reactivity towards an electrophilic reagent, for the following 
(i) Benzene
(ii) Toluene 
(iii) Chlorobenzene  
(iv) Phenol
would be: 

1. (i) > (ii) > (iii) > (iv)

2. (ii) > (iv) > (i) > (iii)

3. (iv) > (iii) > (ii) > (i)

4. (iv) > (ii) > (i) > (iii)

Select the pair of isostructural species.

Passage cells are thin-walled cells found in: