ପୂର୍ବବର୍ଷ NEET ପ୍ରଶ୍ନ-ସମାଧାନ L-9
ପ୍ରଶ୍ନ: $100^{\circ} \mathrm{C}$ ରେ $6.5 \mathrm{~g}$ ରେ ଏକ ରସରୂପ ର ଏକ ବିଷାପନର ବାଷ୍ପ ଶକ୍ତି $100 \mathrm{~g}$ ଜଳରେ $732 \mathrm{~mm}$ ହୁଏ। $\mathrm{K}_{\mathrm{b}}=0.52$ ହେଲେ, ଏହି ବିଷାପନର ଉଚ୍ଚତା ହେବ $102^{\circ} \mathrm{C}$, $103^{\circ} \mathrm{C}$, $101^{\circ} \mathrm{C}$, କିମ୍ବା $100^{\circ} \mathrm{C}$?
A) $102^{\circ} \mathrm{C}$
B) $103^{\circ} \mathrm{C}$
C) $101^{\circ} \mathrm{C}$
D) $100^{\circ} \mathrm{C}$
ଉତ୍ତର: $101^{\circ} \mathrm{C}$
ସମାଧାନ:
ଯୋଗାଯୋଗ କରିବା ଯୋଗୁଁ,
$$
\begin{aligned}
& \mathrm{W}{\mathrm{S}}=6.5 \mathrm{~g}, \mathrm{~W}{\mathrm{A}}=100 \mathrm{~g} \
& \mathrm{p}{\mathrm{S}}=732 \mathrm{~mm} \text { of } \mathrm{Hg} \
& \mathrm{k}{\mathrm{b}}=0.52, \mathrm{~T}{\mathrm{b}}^{\mathrm{O}}=100^{\circ} \mathrm{C} \
& \mathrm{p}^0=760 \mathrm{~mm} \text { of } \mathrm{Hg} \
& \frac{p^o-p_s}{p^o}=\frac{n_2}{n_1} \
& \Rightarrow \frac{760-732}{760}=\frac{n_2}{\frac{100}{18}} \
& \Rightarrow \mathrm{n}2=0.2046 \mathrm{~mol} \
& \Delta \mathrm{T}{\mathrm{b}}=\mathrm{K}{\mathrm{b}} \times \mathrm{m} \
& \mathrm{T}{\mathrm{b}}-\mathrm{T}{\mathrm{b}}^{\circ}=k_b \times \frac{n_2 \times 1000}{w_{A(g)}} \
& \Rightarrow \mathrm{T}{\mathrm{b}}-100^{\circ} \mathrm{C}=\frac{0.52 \times 0.2046 \times 1000}{100}=1.06 \
& \Rightarrow \mathrm{T}{\mathrm{b}}=101.06^{\circ} \mathrm{C}
\end{aligned}
$$