Calculating the Energy Needed to Heat Magnesium: A Challenge!

In summary, the conversation is about calculating the energy required to raise the temperature of magnesium using the temperature-dependent molar specific heat capacity equation. The constants for magnesium are given and the person is struggling to calculate the energy using the formula. They suggest trying to use the integral of the specific heat capacity function to solve the problem.
  • #1
davidray
7
0
Any help on this quistion would be greatly appreciated. I have no idea ho to answere it, and can't find anything in my nothes or books anywhere.

The temperature-dependent molar specific heat capacity at constant pressure of many substances is given by: c =a+2bT−cT^−2

For magnesium, the numerical values of the constants are: a=25.7, b=3.13x10^-3, c=3.27x10^5

where c has units J/Kxmol

Calculate the energy required to raise the temperature of 15g of Megnesium from 30 C to 300 C.

I have tried using the formula to qenerate a specific heat capacity for each temperature, but just seem to get crazy numbers that don't make any sense!

Thanks for the help!
 
Physics news on Phys.org
  • #2


When S.H is a constant, c, then energy=c x delta T

which looks like what you'd get from integral of c from T1 to T2

So try integral of c from T1 to T2 where c is a function of T.
 

1. How do you calculate the energy needed to heat magnesium?

To calculate the energy needed to heat magnesium, you can use the formula Q = mcΔT, where Q is the energy (in Joules), m is the mass of magnesium (in grams), c is the specific heat capacity of magnesium (in J/g°C), and ΔT is the change in temperature (in °C).

2. What is the specific heat capacity of magnesium?

The specific heat capacity of magnesium is approximately 1.02 J/g°C. This value may vary slightly depending on the purity and form of the magnesium being used.

3. How do you determine the change in temperature for heating magnesium?

The change in temperature can be determined by subtracting the initial temperature from the final temperature. For example, if the initial temperature of the magnesium is 20°C and the final temperature is 100°C, the change in temperature would be 100°C - 20°C = 80°C.

4. Can you calculate the energy needed to heat a specific amount of magnesium without knowing the specific heat capacity?

No, the specific heat capacity is a crucial component in the calculation of energy needed to heat magnesium. Without this value, the calculation cannot be accurately completed.

5. How do you convert the energy needed to heat magnesium from Joules to calories?

To convert from Joules to calories, you can use the conversion factor 1 calorie = 4.184 Joules. Simply divide the energy in Joules by 4.184 to get the equivalent amount in calories.

Similar threads

  • Introductory Physics Homework Help
Replies
1
Views
573
  • Advanced Physics Homework Help
Replies
4
Views
5K
  • Introductory Physics Homework Help
Replies
2
Views
664
  • Introductory Physics Homework Help
2
Replies
41
Views
4K
Replies
5
Views
2K
Replies
1
Views
547
  • Introductory Physics Homework Help
Replies
6
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
703
  • Introductory Physics Homework Help
Replies
12
Views
1K
Back
Top