Question

The reaction of hydrochloric acid and sodium hydroxide is exothermic

HCl +NaOH --> NaCl + H2O

In one experiment, a student placed 50.0 mL of 1.00 M HCl at 25.5 oC in a coffee cup calorimeter. To this was added 50.0 mL of 1.00 M NaOH solution, also at 25.5 oC. The mixture was stirred and the temperature rose to 37.8 oC. What is the heat of reaction in joules per mole of HCl? Assume the specific heat of the solutions is 4.184 J/g oC, densities are 1.00 g/mL, and no heat is lost to the cup or to the air.

Answer 1

mols HCl = M x L = 1.00 x 0.050 = 0.050
mols NaOH = M x L = 0.050
Total volume = 100 mL

qrxn = mass x specific heat x (Tfinal-Tinitial) = 100 g x 4.184 x (37.8-25.5) = ? J/0.050 mol HCl
So how much is q for 1 mol?