How much heat is required to raise the temperature of 1 kg of ice at -30° C to steam that is 110° C?

Question

How much heat is required to raise the temperature of 1 kg of ice at -30° C to steam that is 110° C?

Answer 1

These types of problems should be done in steps.

Step 1:  heat to raise 1 kg ice from -30ºC to 0ºC

q = mC∆T = (1000 g)(2.09 J/g/deg)(30 deg) = 62,700 J = 62.7 kJ (2.09 is the C for ice)

 

Step 2:  heat to melt 1 kg ice (no change in temp)

q = m∆Hfusion = (1000 g)(334 J/g) = 334,000 J = 334 kJ

 

Step 3:  heat to raise 1 kg H2O from 0ºC to 100ºC

q = mC∆T = (1000 g)(4.184 J/g/deg)(100 deg) = 418,400 J = 418.4 kJ(4.184 is the C for liquid H2O)

 

Step 4: heat to turn 1 kg H2O from liquid to vapor (no change in temp)

q = m∆Hvap = (1000 g)(2260 J/g) = 2,260,000 J = 2260 kJ

 

Step 5: heat to raise temp of 1 kg steam from 100º to 110º

q = mC∆T = (1000 g)(1.89 J/g/deg) = 1890 J = 1.89 kJ (1.89 is the C for H2O steam)

 

ADD UP ALL THE KJ OF HEAT TO GET THE FINAL ANSWER