How do I find ΔHrxn for this reaction?
Zinc metal reacts with hydrochloric acid according to the following balanced equation.
#"Zn(s)+2HCl(aq)→ZnCl"_2"(aq)+H"_2"(g)"#
When 0.105 g of Zn(s) is combined with enough HCl to make 50.0 mL of solution in a coffee-cup calorimeter, all of the zinc reacts, raising the temperature of the solution from 21.5 ∘C to 24.3 ∘C.
Find ΔHrxn for this reaction as written. (Use 1.0 g/mL for the density of the solution and 4.18 J/g⋅∘C as the specific heat capacity.)
Zinc metal reacts with hydrochloric acid according to the following balanced equation.
When 0.105 g of Zn(s) is combined with enough HCl to make 50.0 mL of solution in a coffee-cup calorimeter, all of the zinc reacts, raising the temperature of the solution from 21.5 ∘C to 24.3 ∘C.
Find ΔHrxn for this reaction as written. (Use 1.0 g/mL for the density of the solution and 4.18 J/g⋅∘C as the specific heat capacity.)
1 Answer
There are two heat transfers to consider:
#q_1 color(white)(m)+ color(white)(m)q_2 = 0#
In this problem,
∴
Note: The answer can have only two significant figures, because that is all you gave for the density of the solution and for the change in temperature.