4. A calorimeter contains 500 g of water at 25°C. You place a cold pack containing 100 g of crystalline ammonium nitrate inside the calorimeter. When the ammonium nitrate finishes dissolving, the temperature of the water inside the calorimeter is 9.3°C. The specific heat of water is 4.18 J/g–°C. What is the enthalpy of fusion (ΔHf) of the ammonium nitrate? (Show your work.) Where necessary, use q = mHf.
4 answers
this one I definitely am confused on Dr B, i tried remembering but nothing
I'm curious. Do you mean delta H formation or delta H fusion or could you mean delta H solution
it would probably be fusion, right.... based on the rest of the question? since it's asking for specific heat
OK, so I'm guessing that you're guessing as to the meaning. If you want the delta H solution here is how to go about it.
q = mass H2O x specific heat H2O x (Tfinal-Tinitial)
q = 500 x 4.18 x (9.3-25) = -32,813 joules and that is the result 2ith 100 g NH4NO3. mols NH4NO3 = 100 g x (1 mol/80g) = 1.25
Then 32,813/1.25 = 26,250 or 26.2 kJ/mol.
q = mass H2O x specific heat H2O x (Tfinal-Tinitial)
q = 500 x 4.18 x (9.3-25) = -32,813 joules and that is the result 2ith 100 g NH4NO3. mols NH4NO3 = 100 g x (1 mol/80g) = 1.25
Then 32,813/1.25 = 26,250 or 26.2 kJ/mol.