Chemical Forums
Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: stevehjerpe on June 27, 2009, 12:25:33 AM
-
I am not sure how to set up the below problem.
When 25.0 mL of 1M H2SO4 is added to 50.0mL of 1M NaOH at 25C in a calorimeter, the temperature changes to 33.9C. Assuming spec heat of 4.18J/gC and the density of 1.00g/mL (and the calorimeter is not included in equation), calculate the delta H in KJ for the reaction?
-
ΔH = mcΔT
mass is in grams
c is the specific heat
ΔT is the change in temperature
ΔH is in Joules
-
I am not sure how to set up the below problem.
When 25.0 mL of 1M H2SO4 is added to 50.0mL of 1M NaOH at 25C in a calorimeter, the temperature changes to 33.9C. Assuming spec heat of 4.18J/gC and the density of 1.00g/mL (and the calorimeter is not included in equation), calculate the delta H in KJ for the reaction?
First, just write a balanced reaction that's happening.
Then, figure out which of the reactants is the limiting reactant, and how many moles of each are reacting.
Finally you can worry about heat. Take UG's advice and remember that any heat gained by the calorimeter is given off by the reaction, i.e.
$$ q_{calorimeter} = - q_{reaction} /$$