In order to measure the enthalpy change for this reaction, 1.25g of NH4NO3 is dissolved in enough water to make 25.0mLof solution. The initial temperature is 25.8 C and the final temperature (after the solid dissolves) is 21.9 C
Calculate the change in enthalpy for the reaction inkJ (Use 1.0 g/mL as the density of the solution and 4.18 J/g*C as the specific heat capacity.)
Anonymous
Favorite Answer
If 1.0g/ml is the density of the solution then
25.0ml(1g/ml) = 25g NH4NO3
Use q = mc∆t
q = 25g(4.184)(3.9) = 408 joules
Hurley
The best answer is correct, for those of you using pearson remember your answer needs to be in kJ/mol. Divide his 408J by 1,000 and then divide by the moles of NH4NO3 (.015625). The answer should come out to about 26.112 or 26kJ/mol with sig figs
Anonymous
where did u get the 3.9 from?