# Answer to Question #17063 in Organic Chemistry for Kenton

Question #17063

(a) When a 3.88-g sample of solid ammonium nitrate dissolves in 60.0 g of water in a coffee-cup calorimeter (Figure 5.17), the temperature drops from 23.0 oC to

18.4 oc. Calculate H (in kJ/ mol NH4N03) for the solution process

NH4NO3(S) ----> NH4 +(aq) + N03 - (aq)

Assume that the specific heat of the solution is the same as that of pure water.

(b) Is this process endothermic or exothermic?

18.4 oc. Calculate H (in kJ/ mol NH4N03) for the solution process

NH4NO3(S) ----> NH4 +(aq) + N03 - (aq)

Assume that the specific heat of the solution is the same as that of pure water.

(b) Is this process endothermic or exothermic?

Expert's answer

a)

Molar mass of NH4NO3 = 14+4+14+48 = 80 g/mol

So, 3.88 g is equal to

3.88/80 = 0.0485 mol

Now, mass of soln = 60+3.88 g = 63.88 g

Heat absorbed

= 63.88x4.18x(23-18.4) = 1228 J

So, 0.0485 mol absorbs 1228 J

1 mol

absorbs 25319 J

So, heat of dissolution of NH4NO3 is 25.319

kJ/mol

b)

This process is endothermic.

Molar mass of NH4NO3 = 14+4+14+48 = 80 g/mol

So, 3.88 g is equal to

3.88/80 = 0.0485 mol

Now, mass of soln = 60+3.88 g = 63.88 g

Heat absorbed

= 63.88x4.18x(23-18.4) = 1228 J

So, 0.0485 mol absorbs 1228 J

1 mol

absorbs 25319 J

So, heat of dissolution of NH4NO3 is 25.319

kJ/mol

b)

This process is endothermic.

Need a fast expert's response?

Submit orderand get a quick answer at the best price

for any assignment or question with DETAILED EXPLANATIONS!

## Comments

Assignment Expert23.02.18, 17:30Dear Monica Blanco,

please use panel for submitting new questions

Monica Blanco21.02.18, 21:59Calculate the minimum value of ∆S (J mol-1 K1) associated with dissolving NaNO3 in water at 23oC. For this process ∆H=25.41 kJ mol-1.

Assignment Expert04.01.17, 13:51Dear Jake

Questions in this section are answered for free. We work on all questions

and publish answers after verification. There is no guarantee of answering

certain question but we are doing our best. Although if you have serious

assignment that requires large amount of work and hence cannot be done for

free you can submit it as assignment and our experts will surely assist you.

Jake30.12.16, 18:58It should be exothermic

## Leave a comment