[Ilikecats12344]

I know the equation for enthalpy change = energy change / moles of reactant. The exercise I have to do is to find the enthalpy change per mole of solid reactant. I have already done the calculations to find out how many moles in the solid and I already have found the energy change. Do I use the moles in the solid I got before hand or do I have to divide by something so it's just 1 mole I'm confused!

[Borek]

As you said - just divide energy change by the number of moles.

[Ilikecats12344]

Oh I see, just to confirm this is correct say I have zinc and the number of moles is 0.05 and the energy change of said reaction is 3.24, I would just divide 3.24/0.05 and I'd have it PER mole? If so thank you for clarifying

[Borek]

Yes.

It is just like using simple proportion. To use your numbers, you know there were 3.24 (of whatever) produced and 0.05 moles reacted, and you are interested in how much would be produced per mole. So the proportion you need is

[tex]\frac {3.24} {0.05\ moles} = \frac x {1\ mole}[/tex]

Solve for x (actually that means "do nothing", as x/1 = x).

[Ilikecats12344]

Thanks alot!