Question

data i got from the experment in the lab.

1- "the NH₃ + HCl reaction "

2- "ammonium chloride into water"

Time	Temperature		Time	Temperature
0.00	21.7		0.00	21.7
0.25	21.7		0.25	21.7
0.50	21.6		0.50	21.7
0.75	21.6		0.75	21.7
1.00	21.6		1.00	21.7
1.25	21.6		1.25	21.7
1.50	21.6		1.50	21.7
1.75	21.6		1.75	21.7
2.00	21.5		2.00	21.7
2.25	21.4		2.25	21.7
2.50	21.4		2.50	21.6
2.75	21.4		2.75	21.6
3.00	21.4		3.00	21.6
3.25	27.6		3.25	21.3
3.50	27.9		3.50	20.5
3.75	27.9		3.75	20.4
4.00	27.9		4.00	20.4
4.25	27.8		4.25	20.4
4.50	27.8		4.50	20.4
4.75	27.7		4.75	20.4
5.00	27.6		5.00	20.4
5.25	27.6		5.25	20.4
5.50	27.5		5.50	20.4
5.75	27.5		5.75	20.4
6.00	27.4		6.00	20.4
6.25	27.4		6.25	20.4
6.50	27.3		6.50	20.5
6.75	27.3		6.75	20.4
7.00	27.2		7.00	20.4
7.25	27.2		7.25	20.4
7.50	27.2		7.50	20.4
7.75	27.2		7.75	20.4
8.00	27.1		8.00	20.4

questions:

1) Use your data and the plots you made to calculate ΔH for the two reactions you studied in this experiment.

2) Use the two ΔHs you just calculated and the information in the background to calculate the enthalpy of formation of solid ammonium chloride.

Answer 1

1) see we have to use this data that specific heat of water or calorimeter = 4.19 kJ/kg^oC

so using above and Hess's law that

we know C , n=1 for both reactions , now just determine for both the reaction and we will get the value of FOR both the reactions as below:

     

2).

now using two we can calculate the enthalpy of formation of solid ammonium chloride is

(this is because once NH3 and HCL reacts the solid NH4CL is formed but it was in the aquous solution so we subtracted the energy which was delivered when aquous becomes the solid NH4CL opposite of reaction 2)

this is what we will get , but i think if you provide the exact value of C in your experiment then everything else will be precise.