Question

Nitrogen dioxide, NO2(g) (Delta.Hf = 33.84 kJ/mol), is decomposed according to the following reaction:

2 upper N upper O subscript 2 (g) right arrow upper N subscript 2 (g) plus 2 upper O subscript 2 (g).

What is the enthalpy change when 2.50 mol of nitrogen dioxide decomposes?
Use Delta H r x n equals the sum of delta H f of all the products minus the sum of delta H f of all the reactants..

13.5 kJ of energy released
13.5 kJ of energy absorbed
84.6 kJ of energy released
84.6 kJ of energy absorbed

Answer 1

Answer:

C

Explanation:

84.6 kJ of energy released when 2.50 moles of nitrogen dioxide is decomposed.

Answer 2

The change in enthalpy of the reaction when 2.5 mole of nitrogen dioxide is decomposed.

What is enthalpy of reaction?

Enthaply of the reaction gives idea about the total amount of heat absorbed or released during any chemical reaction.

Given chemical reaction is:

2NO₂ → N₂ + 2O₂

From the stoichiometry of the reaction it is clear that:

2 moles of NO₂ = produces 1 mole of N₂

2 moles of NO₂ = produces 2 mole of O₂

So, 2.5 moles of NO₂ = produces 1/2×2.5 = 1.25 moles of N₂

and 2.5 moles of NO₂ = produces 2.5 mole of O₂

Hf of N₂ = 0

Hf of O₂ = 0 (as enthalpy of formation of elemental form is always zero)

Hf of NO₂ = 33.84 kJ/mol (given)

Enthalpy of the reaction on the basis og given equation in question is:

ΔHrxn = (0 + 0) - 2.5×33.84 kJ/mol

ΔHrxn = - 84.6kJ

Hence 84.6 kJ of energy is released.

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https://brainly.com/question/11753370