\( = 0.687\,^oC = \,\,0.69\,^oC\)
\(\Delta {T_f}\, = \,\,{({T_f})_{solvent}}\, = \,\,{({T_f})_{solution}}\)
\(0.69\,\, = \,\,0\,\, - \,\,{({T_f})_{solution}}\,\)
\( \Rightarrow \,\,\,{({T_f})_{sol}}\, = \,\, - \,\,0.69\,^oC\)
[આણ્વીય દળ ${Cu}: 63.54\, {u}, {S}: 32\, {u}, {O}: 16 \,{u}, {H}: 1\, {u}]$