Question

8. The addition of HCl(aq) to a silver nitrate solution precipitates silver chloride according to the following reaction: AgNO3 (aq) + HCl (g) AgCl(s) + HNO3 (aq) ΔHrxn = ?

a. When 50.00mL of 0.100 M AgNO3 is combined with 50.00 mL of 0.100 M HCl in a coffee-cup calorimeter, the temperature of solution changed from 23.40°C to 24.21 °C. Calculate ΔHrxn for this reaction as written. Assume the density of the solution is 1.00g/mL and the specific heat capacity Cs = 4.18 J/g.°C.

b. Write a net ionic equation for the reaction.

Answer 1

AgNO3 (aq) + HCl (g) AgCl(s) + HNO3

Volume of solution = 100 ml

Mass = 100g

therefore delta H = ms delta T = 100* 4.18 J * (24.21-23.40)

= 338.58 grams

b)

1 mole of Ag NO3 contains 1 moles of Ag+ and 1 mole of NO−3 .
Ag+ (aq) + NO−3 (aq) + H+ (aq) + Cl− (aq) -------->
Ag+ Cl− (s) + H+ (aq) + NO−3 (aq)
the net equation is
Ag+ (aq) + Cl− (aq) ----> Ag+ Cl− (s)