According to the following reaction, how much energy is evolved during the reaction of 2.50 L B₂H₆ and 5.65 L Cl₂(both gases are initially at STP)? The molar mass of B₂H₆is 27.67 g mol^-1. B₂H₆(g)+ 6Cl₂(g)→ 2BCl₃(g)+ 6HCl(g)Δ_rH°= -1396 kJ

Question

Quizplus · Accepted Answer

At STP, 1 mole of gas occupies 22.4 L. Therefore, 2.50 L of B2H6 is 2.50/22.4 = 0.1116 moles, and 5.65 L of Cl2 is 5.65/22.4 = 0.2522 moles. The reaction requires 6 moles of Cl2 for every mole of B2H6, so B2H6 is the limiting reactant. The reaction of 1 mole of B2H6 releases 1396 kJ, so 0.1116 moles release 0.1116 * 1396 = 155.8 kJ, which is approximately 156 kJ.

According to the Following Reaction, How Much Energy Is Evolved