Question

Given the balanced equation below for the highly exothermic reaction of aluminum with oxygen to form aluminum oxide: What is the value of ΔH when 1.00 mol of aluminum reacts? What is the value of ΔH when 5.23 g of aluminum reacts? What is the value of ΔH when 6.17 L of oxygen gas at STP reacts with excess aluminum? A certain reaction releases 6881 kJ of heat.

What is the value of ΔH when 1.00 mol of aluminum reacts?

a) -6881 kJ
b) 6881 kJ
c) -1720.25 kJ
d) 1720.25 kJ

Answer 1

The value of ΔH when 1.00 mol of aluminum reacts is -1720.25 kJ.

Step-by-step explanation:

The value of ΔH when 1.00 mol of aluminum reacts can be determined by using the balanced equation: 4Al(s) + 3O2(g) -> 2Al2O3(s). From the equation, we can see that 4 mol of aluminum are needed to form 2 mol of aluminum oxide. Given that the equation releases 6881 kJ of heat, we can set up a proportion to find the value of ΔH when 1.00 mol of aluminum reacts:

(6881 kJ)/(4 mol Al) = x/(1 mol Al)

Solving for x, we find that ΔH = -1720.25 kJ. Therefore, the answer is option c) -1720.25 kJ.