Identify the correct answer.

Identify the major product C formed in the following reaction sequence :

$$ \mathrm{CH}_3-\mathrm{CH}_2-\mathrm{CH}_2-\mathrm{I} \xrightarrow{\mathrm{NaCN}} \mathrm{A} $$

$$\mathrm{\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{Partial\,hydrolysis}^{O{H^ - }}} B\mathrel{\mathop{\kern0pt\longrightarrow} \limits_{B{r_2}}^{NaOH}} \mathop C\limits_{(major)}}$$

Given below are certain cations. Using inorganic qualitative analysis, arrange them in increasing group number from 0 to $$\mathrm{VI}$$.

A. $$\mathrm{Al}^{3+}$$

B. $$\mathrm{Cu}^{2+}$$

C. $$\mathrm{Ba}^{2+}$$

D. $$\mathrm{Co}^{2+}$$

E. $$\mathrm{Mg}^{2+}$$

Choose the correct answer from the options given below.

The work done during reversible isothermal expansion of one mole of hydrogen gas at $$25^{\circ} \mathrm{C}$$ from pressure of 20 atmosphere to 10 atmosphere is (Given $$\mathrm{R}=2.0 \mathrm{~cal} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$$)