Consider the following reaction: 2 Mg + O2 → 2 MgO ΔH rxn = -1203 kJ
Calculate the amount of heat (in kJ) associated with complete reaction of 4 moles of Mg.
How do I set this up correctly?
2406
Assuming O2 is in excess:
2 moles of MgO=2 moles of Mg=1 moles of O2
So,
4 moles of Mg*(-1203kJ/2 moles of Mg)=???
Well, it's quite simple! To calculate the amount of heat associated with the complete reaction of 4 moles of Mg, you can use the concept of stoichiometry.
First, you need to determine the stoichiometric ratio between Mg and the heat released. According to the balanced equation, the ratio is 2:1. So, for every 2 moles of Mg reacted, the amount of heat released is 1203 kJ.
Now, to find out the amount of heat released with 4 moles of Mg, you can set up a proportion:
2 moles of Mg / 1203 kJ = 4 moles Mg / x kJ
Cross-multiplying and solving for x:
2x = 4 * 1203
x = (4 * 1203) / 2
Calculating that gives us:
x = 2406 kJ
Therefore, the amount of heat associated with the complete reaction of 4 moles of Mg is 2406 kJ. But don't worry, it's a lot safer than it sounds!
To calculate the amount of heat associated with the complete reaction of 4 moles of Mg, you can use the given ΔH value to determine the heat released per mole of reaction. Here's how to set it up correctly:
1. Start with the given equation: 2 Mg + O2 → 2 MgO ΔH rxn = -1203 kJ
2. Note that the ΔH value represents the heat released for 2 moles of Mg reacting. We need to calculate the heat released for 4 moles of Mg, so we need to double the ΔH value.
3. Calculate the heat released per mole of reaction:
ΔH per mole = ΔH rxn / number of moles of reaction
ΔH per mole = -1203 kJ / 2 moles
ΔH per mole = -601.5 kJ/mol
4. Multiply the ΔH per mole by the number of moles of Mg to calculate the total heat released for 4 moles of Mg:
Heat released = ΔH per mole * number of moles of Mg
Heat released = -601.5 kJ/mol * 4 moles
Heat released = -2406 kJ
Therefore, the amount of heat associated with the complete reaction of 4 moles of Mg is -2406 kJ.
To calculate the amount of heat associated with the complete reaction of 4 moles of Mg, you can use the given enthalpy change of the reaction and apply it to the stoichiometry of the reaction.
The given reaction is: 2 Mg + O2 → 2 MgO (ΔH rxn = -1203 kJ)
From the balanced equation, we can see that 2 moles of Mg are required to produce 2 moles of MgO. Therefore, the molar ratio of Mg to MgO is 2:2, which simplifies to 1:1.
Since the reaction is exothermic (ΔH rxn = -1203 kJ), it means that for every mole of Mg reacted, 1203 kJ of heat is released.
Now, to calculate the amount of heat associated with the complete reaction of 4 moles of Mg, we can set up a proportion:
(1 mole of Mg / 1203 kJ) = (4 moles of Mg / x kJ)
Solving for x, we find:
x = (4 moles of Mg * 1203 kJ) / 1 mole of Mg
x = 4812 kJ
Therefore, the amount of heat associated with the complete reaction of 4 moles of Mg is 4812 kJ.