Thread: phys quiz question please help me, thank you

The quantity of heat Q that changes the temperature T of a mass m of a substance is given by Q = mcT, where c is the specific heat capacity of the substance. For example, for H20, c = 1 cal/g°C. And for a change of phase the quantity of heat Q that changes the phase of a mass m is Q = mL, where L is the heat of fusion or heat of vaporization of the substance. For example, for H20 the heat of fusion is 80 cal/g or 80 kcal/kg, and the heat of vaporization is 540 cal/g or 540 kcal/kg. Use these relationships to determine the number of calories to change

(a) 0.6 kg of 0°C ice to 0.6 kg 0°C ice water
kcal
(b) 0.6 kg of 0°C ice water to 0.6 kg 100°C boiling water
kcal
(c) 0.6 kg of 100°C boiling water to 0.6 kg l00°C steam
kcal
(d) 0.6 kg of 0°C ice to 0.6 kg 100°C steam
kcal

Originally Posted by johnjohn

The quantity of heat Q that changes the temperature T of a mass m of a substance is given by Q = mcT, where c is the specific heat capacity of the substance. For example, for H20, c = 1 cal/g°C. And for a change of phase the quantity of heat Q that changes the phase of a mass m is Q = mL, where L is the heat of fusion or heat of vaporization of the substance. For example, for H20 the heat of fusion is 80 cal/g or 80 kcal/kg, and the heat of vaporization is 540 cal/g or 540 kcal/kg. Use these relationships to determine the number of calories to change

(a) 0.6 kg of 0°C ice to 0.6 kg 0°C ice water
kcal
(b) 0.6 kg of 0°C ice water to 0.6 kg 100°C boiling water
kcal
(c) 0.6 kg of 100°C boiling water to 0.6 kg l00°C steam
kcal
(d) 0.6 kg of 0°C ice to 0.6 kg 100°C steam
kcal

Hello,

you only have to use all the given constants:

(a):

(b):

(c):

(d); Add the results (a)+(b)+(c)

A personal question: I'm used to measure the difference of temperatures in Kelvin and if I remember correctly the unit cal or kcal is not allowed since 1979