Question

How much heat is required to change a 49.1 g ice cube from ice at -10.2°C to water at 36°C? (if necessary, use cice=2090 J/kg°C and csteam= 2010 J/kg°C)

How much heat is required to change a 49.1 g ice cube from ice at -10.2°C to steam at 118°C?

Answer 1

1). Heat is needed first to raise the temperature of ice to 0 degree celsius then to convert ice into water then to raise the temperature of water from 0 degree celsius to 36 degree celsius.

then we'll have

  .................................(1)

where c_ice= specific heat of ice,

T_fc= Final Temperature of ice state

T_ic= Initial Temperature of ice state

L= Latent Heat of fusion of ice into water, L= 334 J/gm

c_water= specific heat of water,

T_fw= Final Temperature of water state

T_iw= Initial Temperature of water state

Then using all above values and given values in equation 1,

  

  (ANS)............................(2)

2). Now on this process more heat will be needed to raise the temperature of converted water from 36 degree celsius to 100 degree celsius, then to convert it into steam and then finally to raise the temperature of steam to 118 degree celsius.

then ................(3)

where c_water= specific heat of water,

T'_fw= Final Temperature of water state

T_i'w= Initial Temperature of water state after the process in 1st part

c_steam= specific heat of steam,

T_fs= Final Temperature of steam

T_is= Initial Temperature of steam

L_vap= Latent Heat of vaporisation of water into steam, L= 2264.76 J/gm

Then using all the above values, given values and equation 2 in equation 3,

  

  

(ANS)