Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

please show all work I am confused on how to get it. 54.0 g aluminum at 50.0 o C

ID: 102674 • Letter: P

Question

please show all work I am confused on how to get it.

54.0 g aluminum at 50.0oC is dumped into water at 38.5oC. The water warms to 40.0oC. (10 pt)

What is specific heat capacity of aluminum?                                                                  

           a) ____________

What is molar heat capacity of aluminum?                                                                               

b) ____________

When 10.0 g ammonium nitrate is dissolved in 50.0 g water at 25.0oC, the final temperature of the solution is 20.0oC.

a. What is the q of the water? (SH water = 4.20 J/g K) (10 pt)

qH2O _________

b. What is the molar change in enthalpy (H in kJ/mol NH4NO3) for the solution process?

H ___________

Explanation / Answer

heat lost by Al = heat gained by water

mass of Al*SAl*DT = mass of water*S*DT

   54*s*(50-40) = mass of water*4.184*(40-38.5)

mass of water not given


2)

a) q of the water = m*s*DT

                   = (50)*4.2*(25-20)

                   = 1050 joule

qH2O = 1050 joule

b. no of mol of Al(NO3)3 dissolved = 10/213 = 0.047 mol

     molar change in enthalpy (H) = -q/n

                                    = -1.05/0.047

           DHrxn = -22.3 kj/mol