Question

we added 100.0 ml of deionized water with 5.521 g ammonium chloride

initial temp 22.8 degree celcuis

final temp 19.2 degree celcius

calculate and show the steps for

1- total mixture mass in cup

2-change in temp for the surrounding

3-heat flow of the surrounding in cup in kj

4-heat flow of system in cup qrxn in kj

5- inintial moles of NH4CI

6-delta H rxn in kj (experimental)

7- delta H in kj(theoretical)

8- percent error

Answer 1

(1) density of water = 1g/mL

Total mass = mass of water + mass of NH4Cl

= 100 mL x 1 g/mL + 5.521 g

= 105.521 g

change in temperature = 22.8 - 19.2 == 3.6 ^oC

Moles of NH4Cl = 5.521 g / 53.5 g/mol == 0.1032 moles

Total heat flow = mC(T2-T1)

= 105.521 g X 4.18 J/g K x (3.6)

= 1.587 kJ

Here final temperature decreased means the reaction is endothermic

So, the heat is taken from surroundings.

Amount of heat taken from surroundings = 1.587 kJ

The remianing are experimental based calculations.