[kimi85]

A "coffee-cup calorimeter contains 100 ml of 0.300 M HCl at 20.3^oC.  When 1.82 g Zn is added, the temperature rises at 30.5^oC.  What is the heat of reaction per mole Zn? There is no heat lost to the H₂ (g) that escapes.

I really can't get the correct answer. It's -285 kJ/mol

Thank you very much.

[Yggdrasil]

I think I know where you may going wrong.  Does all 1.82g of Zn react?

[kimi85]

I think all of it reacts.

[Dan]

I think all of it reacts.

Write a balanced equation, identify the number of moles of HCl and Zn, then determine the limiting reagent.

[kimi85]

Oh I see. Thank you very much.