Can someone please help me??? Zinc metal reacts with hydrochloric acid according

Question

Can someone please help me???

Zinc metal reacts with hydrochloric acid according to the following balanced equation. Zn(s) + 2HCl(aq) rightarrow ZnCl_2 (aq) + H_2(g) When 0.128 g of Zn(s) is combined with enough HCl to make 51.4 mL of solution in a coffee-cup calorimeter, all of the zinc reacts, raising the temperature of the solution from 22.2 degree C to 23.8 degree C. Find delta H_r times n for this reaction as written. (Use 1.0 g/mL for the density of the solution and 4.18 J/g middot degree C as the specific heat capacity.)

Explanation / Answer

since density of solution is 1g/mL,
mass of solution , ms = 51.4 g

1st calculate the heat absorbed by solution for temperature to increase
Qsolution = ms*cs*delta Ts
= 51.4*4.18*(23.8 - 22.2)
= 343.76 J

number of mol of Zn,
n= mass/molar mass
= 0.128 g / 65.4 g/mol
=1.957*10^-3 mol

Hrxn = -Qsolution/n
= - 343.76 J /(1.957*10^-3 mol)
= - 175657 J/mol
= - 175.7 KJ/mol

Answer: - 175.7 KJ/mol

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