Question
how much heat must be added to 5.0 g of solid lead at 30 degrees celcius to convert it to liquid lead at the melting point?
Answers
DrBob222
Note the correct spelling of celsius.
The melting point of Pb is 327.5 C.
q added to raise temperature from 30 C to 327.5C is
q1 = mass Pb x specific heat Pb x delta T. You will need to look up the specific heat Pb. delta T is 327.5-30.
q2 = heat needed to melt Pb at 327.5 C is
q2 = mass Pb x heat fusion Pb.
You will need to look up the heat fusion.
Total q = q1 + q2.
The melting point of Pb is 327.5 C.
q added to raise temperature from 30 C to 327.5C is
q1 = mass Pb x specific heat Pb x delta T. You will need to look up the specific heat Pb. delta T is 327.5-30.
q2 = heat needed to melt Pb at 327.5 C is
q2 = mass Pb x heat fusion Pb.
You will need to look up the heat fusion.
Total q = q1 + q2.
fred
thanks dr.bob
fred
so is the answer 316 joules?
DrBob222
You didn't provide what you used for the melting point or the heat fusion or the specific heat so I don't know it that is right or not. Using 327.5 for m.p. and 22.4 J/g for heat fusion and 0.16 J/g*C, I obtained 350 Joules.