Answer:
16974J of energy are required
Explanation:
The energy required is:
* The energy to heat solid water from -15°C to 0°C using:
q = m*S*ΔT
* The energy to convert the solid water to liquid water:
q = dH*m
* The energy required to increase the temperature of liquid water from 0°C to 75°C
q = m*S*ΔT
The first energy is:
q = m*S*ΔT
m = Mass water = 25g
S is specific heat of ice = 2.03J/g°C
ΔT is change in temperature = 0°C - (-15°C) = 15°C
q = 25g*2.03J/g°C*15°C
q = 761.3J
The second energy is:
q = dH*m
m = Mass water = 25g
dH is heat of fusion of water = 80cal/g
q = 80cal/g*25g
q = 2000cal * (4.184J/1cal) = 8368J
The third energy is:
q = m*S*ΔT
m = Mass water = 25g
S is specific heat of water= 4.184J/g°C
ΔT is change in temperature = 75°C-0°C = 75°C
q = 25g*4.184J/g°C*75°C
q = 7845J
The energy is: 7845J + 8368J + 761J =
16974J of energy are required
