Expert: Paul Klarreich - 10/12/2007

Question
Hello, Good Afternoon, I was wondering if you can help me with the following problem?  Thank you in advance for your time and help.

The latent heat of fusion (solid become liquid) for ice is 79.8 cal/gram.  How much ice can we melt with 1000 calories of heat?

The questions associated with the problem are as follows:

1. Identify the key pieces of information required to solve this problem.
2.  Identify the extraneous information in the background reading.
3.  Explain your strategy for solving this problem.
4.  Solve the problem.  How much ice can you melt with 1000 calories of heat?

There is another problem, if you have time, I wanted to know if you can help me with also?  It is:

Which would require more heat, melting 500 g of 0 C ice or turning 500 g of 100 C water into steam?

A 500 g sample of an unknown material requires 750 calories of heat to raise its temperature by 50 C.  Identify the material.  

Answer
Questioner:   chena
Category:  Advanced Math
Private:  No
 
Subject:  Problem Solving
Question:  Hello, Good Afternoon, I was wondering if you can help me with the following problem?  Thank you in advance for your time and help.

The latent heat of fusion (solid become liquid) for ice is 79.8 cal/gram.  How much ice can we melt with 1000 calories of heat?

The questions associated with the problem are as follows:

1. Identify the key pieces of information required to solve this problem.
2.  Identify the extraneous information in the background reading.
3.  Explain your strategy for solving this problem.
4.  Solve the problem.  How much ice can you melt with 1000 calories of heat?

There is another problem, if you have time, I wanted to know if you can help me with also?  It is:

Which would require more heat, melting 500 g of 0 C ice or turning 500 g of 100 C water into steam?

A 500 g sample of an unknown material requires 750 calories of heat to raise its temperature by 50 C.  Identify the material.
...........................................
Hi, Chena,

It's not at all clear what you want, but I'll see what I can do.


1. The latent heat of fusion (solid become liquid) for ice is 79.8 cal/gram.  How much ice can we melt with 1000 calories of heat?

If  x = the number of grams of the ice

[Don't just say   x = ice.  That gets you nowhere.]

then  79.8 cal/gram times  x  grams = 1000 cal

x  = 1000/ 79.8  

2.  Which would require more heat, melting 500 g of 0 C ice or turning 500 g of 100 C water into steam?

If you do the same thing here, you soon find that you need another piece of information:

latent heat of vaporization (liquid becomes gas) for water is ???????? cal/gram.

3. A 500 g sample of an unknown material requires 750 calories of heat to raise its temperature by 50 C.  Identify the material.

Now you need more vocabulary.  Such as

Specific heat of a substance.

With that, you will be able to handle this.  

Next time, please, tell me what subject you are studying.  Not just Advanced Math -- what is the name of the course, what is the name of the book, what is the name of the section of the book, etc.