[djm9090]

A metal reacts with HCl:

M(s)+3HCl(aq)  MCl₃(aq) + 3/2H₂(g)

ΔH=?

0.321g of M completely reacted with 25.00 mL of HCl while undergoing a 4.95 °C temperature change.
If the molar mass of M is 82.387 g/mol, what is the enthalpy change for the reaction in KJ/mol?

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Do I plug in the mass of HCl when finding q? [q=msΔt]
I'm assuming the density of aqueous HCl is the same as water; 1g/L.
The problem did not give a molar concentration of HCl, just a volume.

Thanks for the help

[rabolisk]

You plug in the mass of the solution, and you should assume that the density and the specific heat of aqueous HCl is the same as water. The molar concentration of HCl is not necessary to solve this problem.