Question

when pure sodium hydroxide is dissolved in water , heat is evolved in a laboratory experiment measure a molar heat of solution of sodium hydroxide the following procedure was followed. to a calorimeter containing 300g of water at 20.0 C and 10.65g of NaOH also at 20.0 C was added. the temperature change which was monitered by digital probe with neglible heat capacity stopped when it reached a temperature of 28.50C if the specific heat of the mixture is 4.184Jg-1c-1 and the small heat capacity of the calorimeter is ignored what is Delta H for the solution of one moleof NaOH? the molar mass of NaOH is 40.09.

Compute the heat generated, Q, using the temperature rise and the mass M and heat capacity C of H2O.
Q = M C (delta T)
delta t is the 8.50 C change in temperature.
Divide Q by the number of moles of NaOH to get the deltaH per mole.

heat of solution is
massH2O*specificheatwater*deltaTH2O =
300g*4.184*(28.50-20.0) = ??joules.

??joules is the heat for 10.65g NaOH.
Convert to ?? joules/40.09 mol.
This is the heat of solution/mol NaOH.
Post your work if you get stuck.

Answer 1

260

Answer 2

usthe following data of the results of a titration with potassium hydroxide (KOH),calculate the concentration of sulfuric (H2SO4.
Burette reading from the titration of 20.0 ml of sulfuric acid with potassium hydroxide
TRIAL INITIAL VOLUME(ML) FINALVOLUME(ML)
1 0.0 23.0
2 23.0 47.0
3 0.0 2305