Question

How much heat is released during the formation of 3.18 mol HCl(g) in this reaction: H2(g)+Cl2(g) → 2HCl(g) with a H of -184.6 kJ. Express your answer in kJ.

Answer 1

Answer: 293.5kJ

Explanation: As can be seen from the given reaction:

`H_2+Cl_2\rightarrow2HCl`

As
`\Delta H` of the reaction is negative, it means the heat is released and the reaction is exothermic.

When 2 moles of HCl are produced, energy released is 184.6kJ

When 3.18 moles of HCl are produced, energy released will be
`=(184.6kJ)/(2)* 3.18=293.5kJ`

Answer 2

The given thermochemical reaction is between hydrogen gas and chlorine gas to form hydrogen chloride.

This can be represented as:

`H_(2)(g)+Cl_(2)(g)-->2HCl(g)` Δ
`H_(reaction)^(0)`=-184.6 kJ/mol

So when two moles of HCl is formed, 184.6 kJ of energy is released.

Calculating the heat released when 3.18 mol HCl (g) is formed in the reaction:

`3.18 molHCl*(184.6kJ)/(2molHCl) =293.5 kJ`

Therefore, 293.5 kJ of heat is released when 3.18 mol HCl is formed in the reaction between hydrogen and chlorine.