MCQ
Pure water super cooled to $-15^o C$ is contained in a thermally insulated flask. Small amount of ice is thrown into the flask. The fraction of water frozen into ice is :
- A$3/35$
- ✓$6/35$
- C$6/29$
- D$2/35$
✓
Answer
Correct option: B.
$6/35$
b
Memass of super cooled water.
Memass of super cooled water.
$\mathrm{m}=\mathrm{mass}$ of ice formed.
now, the heat evolved due to the formation of ice is used to raise the temperature of water from $-15^{\circ} \mathrm{C}$ to $0^{\circ} \mathrm{C}$
$80 m=m \times 0.5 \times[0-(-15)]+(M-m) \times 1 \times 15$
$\frac{m}{M}=\frac{6}{35}$
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