need to figure out how to calculate.
the value of DeltaH for the reaction below is -72kj_____kj of heat are released when 1.0 mole of HBr is formed in this reaction.
H2(g)*Br2(g)> 2HBr(g)
I know the answer is 36 but need help
The reaction as written produces 72 kJ heat and that's for 2 moles HBr. The question is for 1 mole which of course is just half that.
To calculate the amount of heat released when 1.0 mole of HBr is formed in the given reaction, we need to use the information provided about the change in enthalpy (ΔH) for the reaction.
In the balanced chemical equation:
H2(g) + Br2(g) → 2HBr(g)
The stoichiometric coefficient in front of HBr is 2, which means that for every 1 mole of HBr formed, the reaction releases ΔH amount of heat.
Given that ΔH for the reaction is -72 kJ, we can use this information to calculate the heat released when 1.0 mole of HBr is formed.
Since the stoichiometry of the reaction tells us that 2 moles of HBr are formed when the reaction occurs, we can set up a proportion to solve for the heat released when 1.0 mole of HBr is formed:
-72 kJ of heat released / 2 moles of HBr formed = X kJ of heat released / 1 mole of HBr formed
Simplifying the proportion:
(-72 kJ / 2) = (X kJ / 1)
Cross-multiplying:
-72 kJ * 1 = X kJ * 2
-72 = 2X
Solving for X (kJ):
X = -72 / 2
X = -36 kJ
So, when 1.0 mole of HBr is formed in this reaction, -36 kJ of heat is released.