A chemical reaction is run in which 132 joules of work is done by the system amd the internal energy changes by 469 joules. Calculate the amount of heat transferred.
u=q+w I was going to do 469 = q + 132 but I think this is wrong.
I believe the internal energy of a system decreases when work is done by the system so dE = q+w
469 = q +(-132)
q = 469 + 132 = ? Check my thinking.
337
You are correct that the equation u = q + w is used to calculate the change in internal energy (∆u) of a system. However, the equation you wrote, 469 = q + 132, is not correct.
In this case, you have the values for work done by the system (w = 132 J) and the change in internal energy (∆u = 469 J). To calculate the amount of heat transferred (q), you need to rearrange the equation as follows:
∆u = q + w
Substituting the given values:
469 J = q + 132 J
Now, you can solve for q by subtracting 132 J from both sides of the equation:
q = 469 J - 132 J
q = 337 J
Therefore, the amount of heat transferred (q) is 337 joules.
The equation you mentioned, u = q + w, is the correct equation to relate the change in internal energy (u) of a system to the heat transferred (q) and work done (w) on or by the system. However, the values you mentioned in your calculation attempt are not accurate.
In your case, you are given that the work done by the system is 132 joules (w = 132 J), and the change in internal energy is 469 joules (Δu = 469 J).
To solve for the amount of heat transferred (q), you can rearrange the equation as q = Δu - w:
q = 469 J - 132 J
q = 337 J
Therefore, the amount of heat transferred in this chemical reaction is 337 joules.