$\left[\right.$ આપેલ છે $\left.: {K}_{{f}}\left({H}_{2} {O}\right)=1.86\, {~K}\, {~kg}\, {~mol}^{-1}\right]$
\(\Rightarrow \text { Mass of sucrose }=(1000-{x})\, {gm}\)
\(\Rightarrow \text { moles of sucrose }=\left(\frac{1000-{x}}{342}\right)\)
\(\Rightarrow 0.75=\frac{\left(\frac{1000-{x}}{342}\right)}{\left(\frac{{x}}{1000}\right)} \Rightarrow \frac{{x}}{1000}=\frac{1000-{x}}{342 \times 0.75}\)
\(\Rightarrow 256.5 {x}=10^{6}-1000 {x}\)
\(\Rightarrow {x}=795.86\, {gm}\)
\(\Rightarrow \text { moles of sucrose }=0.5969\)
New mass of \({H}_{2} {O}={a}\, {kg}\)
\(\Rightarrow 4=\frac{0.5969}{{a}} \times 1.86 \Rightarrow {a}=0.2775\, {~kg}\)
\(\Rightarrow \text { ice separated }=(795.86-277.5)=518.3 \,{gm}\)
(નજીકનાં પૂર્ણાંકમાં રાઉન્ડ ઑફ) $\left[ K _{ b }=0.52 \,K \,kg \,mol ^{-1}\right]$