Question

Determine the mass of ice initially at -80ºC that would lead to a final temperature of 80ºC when mixed with 100g of water initially at 100ºC.

The answer is 10g, how does one find this answer thank you for helping me.

Answer 1

Mass of water, M = 100 g = 0.1 kg

Initial temperature of ice, = -80℃

Initial temperature of water, = 100℃

Final temperature, = 80℃

Heat gained by the ice at -80℃ = Heat lost by the water at 100℃

● Heat gained by ice to convert from -80℃ to 0℃,

   mass of ice × specific heat of ice × temperature change

Let the mass of ice be m and the specific heat of ice is 2100 J/kg℃.

  

● Heat gained by ice at 0℃ to convert water at 0℃,

  

where is the latent heat of fusion and

● Heat gained by water at 0℃ to convert water at 80℃,

(The specific heat of water is 4200J/kg℃.)

● Heat lost by water at 100℃ to convert water at 80℃,

Heat gained by ice = heat lost by water

answered by: anonymous