Posted by Jon on Thursday, April 3, 2008 at 5:14pm.
The melting point of a solid is 90.0 d/C. What is the heat required to change 2.5 kg of this solid at 40.0 d/C to a liquid? The specific heat of the solid is 390 J/kg-K and its heat of fusion is 4000 J/kg.
I got 2 different answers 2 different ways:
2.5(50)(4000) which is 5.0 x 10^5 J or, 2.5(4000) which is 1.0 x 10^4 J
- physics - DrBob222, Thursday, April 3, 2008 at 5:23pm
This is two problems rolled into one.
q1 = heat required to raise T of solid from 40.0 C to 90.0 C.
q1 = mass x specific heat x delta T.
q2 = heat required to melt the solid once the T has reached 90.0 C.
q2 = mass x heat of fusion.
Total heat = q1 + q2.
- physics - Jon, Thursday, April 3, 2008 at 6:45pm
I read what you said but could it be this also?
specific heat x mass x change in temperature.
answer: 4.9 x 10^4 J
- physics - DrBob222, Thursday, April 3, 2008 at 7:39pm
No, it can't be that.
390*2.5*50 is q1. That's the amount of heat necessary to raise the temperature of the solid from 40 C to its melting point of 90 C. But the total heat is that amount PLUS the amount necessary to melt the solid. That is q2 which is 2.5 kg x 4000 J/kg.
Therefore, the total is
(390*2.5*50) + (2.5*4000) = ??
Answer This Question
More Related Questions
- Physics - The melting point of a solid is 90.0 degrees C. What is the heat ...
- Physics - An unknown mass of a certain solid, initially at 60⁰C, is heated...
- ap chemistry - How much heat is required to heat 19 g of solid silver from 100...
- chem - The specific heat of silver is 0.237 J/goC Its melting point is 961oC . ...
- physics - An unknown mass of a certain solid, initially at 60⁰C, is ...
- science - Specific heat capacity of solid ethanol is 2.419 J/g C. Melting point ...
- chemistry - How much heat is required to heat 28 g of solid silver from 130 ...
- Chemistry - Isopropyl alcohol, C3H7OH is an organic compound. It melts at -89 C ...
- physics - This graph in the figure (Figure 1) shows how the temperature of an ...
- Chemistry - The specfic heat of iron is 0.11cal/g C. The heat of fusion of iron...