Hey, I've been practising chemistry calculations however I just can't seem to get this question right:
Zinc will displace copper from copper (II) sulphate solution according to the following equation:
CuSO4(aq) + Zn(s) ( Cu(s) + ZnSO4(aq)
If an excess of zinc powder is added to 50 cm3 of 1.0 moldm-3 copper(II) sulphate, the temperature increases by 6.3 oC. Calculate the enthalpy change for the reaction.
According to the mark scheme the answer is -26.3 kJmol-1. I got 26334KJmol-1, which is very very wrong.
I did q=mc∆t so 50x4.19x6.3 which equalled 1316.7
To find n I did 1x(50/1000) which equalled 0.05dm-3 and then times that by 1.
Finally I did ∆h=q/n so 1316.7/0.05.
Can anyone see where I went wrong? I think it could be mu second step, finding n as I divided 50 by 1000 but the conc is in moldm-3...