Consider the following reaction, which occurs at standard state: 2CI(g) -- CI2(g) H= -243.4 kJ
If 15.0g of CI is concerted to chlorine, determine the heat released from this reaction.

The heat energy released from the reaction is approximately 51.4791 kJ

Explanation:

The given parameters are;

The heat of the reaction of 2Cl (g) → Cl₂ (g) = -243.4 J

The given mass of Cl being converted to chlorine gas, Cl₂ = 15.0 g

From the reaction for the heat of formation, we have;

2 moles of chlorine produces 1 mole of Cl₂ to release 243.4 kJ of energy per mole of Cl₂

The mass of 1 mole of Cl ≈ 35.453 g

Therefore, from number of moles, n = Mass/(Molar Mass), we have;

The number of moles of chlorine, in 15.0 g of chlorine = 15.0/35.453 ≈ 0.423 moles

Therefore, given that 2 moles of Cl produces 1 mole of Cl₂, we have;

0.423 moles of Cl will produce 0.423/2 ≈ 0.2115 moles of Cl₂

The heat energy released from the reaction is therefore, H ≈ 0.2115 × 243.4 kJ = 51.4791 kJ.

the answer is d. 74.02