Question

✪ Physics ✪
200g of ice at -20°C is mixed with 500g of water at 20°C in an insulating vessel. Final mass of water in vessel is (specific heat of ice = 0.5 cal $\sf g^{-1} \: ^{\circ} C^{-1}$).​

Answer 1

Explanation:

As we know, ice melts at 0°C.

First,

Raising the temperature of ice to 0°C

Heat required = msdT = 200 × 0.5×(20-0)

= 2000 cal

= Heat lost by 500 gm water.

Energy left in water = msdT - 2000 = 500×1×20 - 2000

= 8000 cal.

We further know, ice will need latent heat to change its state.

Which will be equal to = m×L (L for ice is 80cal/gm and m is mass of ice)

=> m × 80 = 8000 cal.

=> m = 100 gm.

Thus, final mass of water will be 500gm + 100gm = 600 gm