How much heat is required to change 10 g of ice at 0o deg C to steam at 100 deg. C?
q1 = heat to melt the ice at zero C.
q1 = mass ice x H fusion.
q2 = heat to move T from zero C to 100 C.
q2 = mass water x specific heat water x delta T.
q3 = heat to turn water into steam at 100 C.
q3 = mass water x H vaporization.
Total Q = q1 + q2 + q3
To calculate the amount of heat required to change a substance from one state to another, we need to consider the heat required for each phase change separately. The total heat required can be determined by adding the heats for each phase change together.
In this case, we need to account for three phase changes:
1. Heating the ice from -273°C to 0°C (heat required to raise the temperature of ice)
2. Melting the ice at 0°C to water at 0°C (heat required for melting)
3. Heating the water from 0°C to 100°C (heat required to raise the temperature of water)
4. Boiling the water at 100°C to steam at 100°C (heat required for vaporization)
Let's calculate the heat for each phase change:
1. Heating the ice from -273°C to 0°C:
The specific heat capacity of ice is 2.09 J/g°C.
Temperature change, ΔT = 0°C - (-273°C) = 273°C
Heat required = mass (10 g) x specific heat capacity x ΔT
= 10 g x 2.09 J/g°C x 273°C
2. Melting the ice at 0°C to water at 0°C:
The heat of fusion (also called heat of melting) for ice is 334 J/g.
Heat required = mass (10 g) x heat of fusion
3. Heating the water from 0°C to 100°C:
The specific heat capacity of water is 4.18 J/g°C.
Temperature change, ΔT = 100°C - 0°C = 100°C
Heat required = mass (10 g) x specific heat capacity x ΔT
4. Boiling the water at 100°C to steam at 100°C:
The heat of vaporization for water is 2260 J/g.
Heat required = mass (10 g) x heat of vaporization
Finally, to calculate the total heat required, add up the heat for each phase change:
Total heat = Heating ice + Melting ice + Heating water + Boiling water
Substitute the values and calculate the total heat required.