NeED HELP A>S>A>P Specific Heat

[lynn0808]

Need help... Dont know how to solve correctly.

a) Determine the amount of energy to raise the temperature of 18kg of carbon from -5celsius to 17celsius.

b) 200g of a certain substance absorbs 7320J of energy and experienced a temperature rise form 5celsius to 30celsius. By calculating its 'C' value, identify as near as possible, the unknown substance.

here's some work I did

delta t= 17-5=12Celsius.
M=18kg
C=709j/kg
energy=cXmXdelta t
709J/kg.K X 18kg X12K
energy=3.28 KJ
=3.3 X10^2?

how do you solve for b. I don't know how to do it. Is this working correct?

 

[hage567]

For (a), please check your delta t.

For (b), you use the same equation you did for (a). You solve for c, the specific heat capacity. The idea is to find this value and look it up in a table and see what material it corresponds to.

 

[baba89]

Hello,

Thank you for reaching out for help with specific heat calculations. I can definitely assist you with solving these problems.

For part a), we can use the formula Q = mcΔT, where Q is the amount of energy, m is the mass, c is the specific heat, and ΔT is the change in temperature. Let's plug in the values we have:

Q = (18kg)(c)(12°C)

We know that the change in temperature is 12°C, and we are trying to find the specific heat (c). We can rearrange the formula to solve for c:

c = Q / (mΔT)

c = (7320J) / (18kg)(12°C)

c = 34.33 J/kg°C

Therefore, the specific heat of carbon is 34.33 J/kg°C.

For part b), we can use the same formula, but rearrange it to solve for the unknown specific heat (c). Let's plug in the values we have:

7320J = (200g)(c)(25°C)

We know that the mass is 200g, the change in temperature is 25°C, and we are trying to find the specific heat (c). We can rearrange the formula to solve for c:

c = Q / (mΔT)

c = (7320J) / (200g)(25°C)

c = 1.464 J/g°C

However, the units for specific heat are typically in J/kg°C, so we need to convert the mass from grams to kilograms:

c = (7320J) / (0.2kg)(25°C)

c = 292.8 J/kg°C

Based on the given information, the substance has a specific heat of approximately 292.8 J/kg°C.

I hope this helps guide you in solving these types of problems in the future. Let me know if you have any other questions or need further clarification. Good luck!