Rearranging equation for heat capacity

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Discussion Overview

The discussion revolves around the rearrangement of an equation related to heat capacity, specifically in the context of determining the specific heat capacity of a substance from experimental data. Participants are addressing a student's approach to solving a problem involving heat transfer and specific heat capacity calculations.

Discussion Character

  • Homework-related
  • Mathematical reasoning
  • Technical explanation

Main Points Raised

  • A student presents a problem involving the measurement of heat capacity for a shiny gold rock, providing specific values for mass, heat absorbed, and temperature change.
  • One participant suggests using the equation q = mc_sΔT to solve for specific heat capacity (c_s) symbolically before substituting numerical values.
  • Another participant expresses confusion about the rearrangement process and questions the clarity of the instructions given by the first poster.
  • A later reply emphasizes the importance of basic algebra in rearranging the equation and reiterates the forum's guideline of not providing final answers but rather guiding towards a solution.

Areas of Agreement / Disagreement

Participants do not appear to reach a consensus on the best method for rearranging the equation or the clarity of the instructions provided. There is a mix of confusion and attempts to clarify the algebraic manipulation involved.

Contextual Notes

Participants have not fully resolved the mathematical steps involved in rearranging the equation, and there are varying levels of understanding regarding the algebraic process required to isolate specific heat capacity.

Who May Find This Useful

This discussion may be useful for students learning about heat capacity, those seeking help with algebraic manipulation in physics or chemistry, and individuals interested in the application of thermodynamic principles in experimental contexts.

FLgirl
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1. To determine whether a shiny gold rock is actually gold, a student decides to measure its heat capacity. She first weighs the rock and finds it has a mass of 4.7g. She then finds that upon absorption of 57.2 J of heat, the temperature of the rock rises from 25 degree Celsius to 57 degree Celsius. Find the specific heat capacity of the substance composing the rock and determine whether the value is consistent with the rock being pure gold.
2. q = m X Cs X temperature change
Cs of gold = 0.128 J/g x Celsius

3. 4.7g X 0.128 J/g x C X 32 C = 19.25
c = 9/temperature change = J/C = 57.2/32 C
4.7g X 32 C / 57.2 J


Actual solution: 57.2 J / 4.7g X 32 CSo my question is; why is 57.2 divided by the others, when if you had brought it over from the other side, wouldn't you divide it BY 57.2?
 
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FLgirl said:
3. 4.7g X 0.128 J/g x C X 32 C = 19.25
c = 9/temperature change = J/C = 57.2/32 C
4.7g X 32 C / 57.2 J

No idea what you are doing here.

q = mc_s\Delta T

Solve for cs. Don't put numbers into the equation yet, just solve symbolically.
 
How do you do that... why are chemists so cryptic
 
Solve symbolically means rearrange so that cs will be on the left hand side of the equation and everything else will be on the right hand side.

There is nothing cryptic here, this is basic algebra that you should learn long ago. And if you have read forum rules you know we don't give final answers, we rather help you solve the problem guiding you in the right direction.
 

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