The value for ΔH° for the reaction below is -72 kJ. How many kJ of heat are released when 1.0 mol of HBr is formed in this reaction?
H2(g) + Br2(l) = 2HBr(g)
What about 1/2 that?
The equation tells you that 2 mols HBr were formed with the release of 72 kJ. So 1 mol must release just 1/2 that? right?
To find out how many kJ of heat are released when 1.0 mol of HBr is formed in this reaction, we can use the given value for ΔH° and the stoichiometric coefficients of the reaction.
The reaction:
H2(g) + Br2(l) = 2HBr(g)
The stoichiometric coefficient of HBr in this reaction is 2. This means that for every 2 moles of HBr formed, the reaction releases -72 kJ of heat.
To find out how many kJ of heat are released when 1.0 mol of HBr is formed, we can set up a proportion:
2 moles HBr / -72 kJ = 1.0 mole HBr / x kJ
Cross-multiplying, we get:
2 moles HBr * x kJ = 1.0 mole HBr * -72 kJ
Simplifying, we find:
2x = -72
Dividing both sides by 2, we get:
x = -36
Therefore, when 1.0 mol of HBr is formed in this reaction, -36 kJ of heat are released.
To determine the amount of heat released when 1.0 mol of HBr is formed in the given reaction, we need to use the concept of stoichiometry and the given value of ΔH°.
The stoichiometric coefficient in the balanced equation shows the mole ratio between the reactants and products. In this case, the coefficient for HBr is 2, meaning that 2 moles of HBr are produced for every 1 mole of Br2 reacted.
Since the ΔH° value is given per mole of the reaction, we can directly use it to calculate the heat released for 1 mole of HBr formed.
To calculate the heat released, we can use the following equation:
Heat released = ΔH° * number of moles of HBr formed
In this case, the number of moles of HBr formed is 1.0 mol.
Substituting the given value and solving for the heat released, we have:
Heat released = -72 kJ/mol * 1.0 mol
Heat released = -72 kJ
Therefore, 72 kJ of heat are released when 1.0 mol of HBr is formed in this reaction.