In other words, this is asking you how to write a proper delta H reaction for formation. Rules: 1. only one mole on product side... so balance reactant side accordingly to get to this. This may mean putting in fractions that look sort of strange. 2. only elemental forms on product side... no compounds! 3. reactants are in standard states of matter for their respective element (i.e. oxygen should be a gas, not a solid, and iron should be a solid, not a liquid, etc.) So... not A because 2 mol product B is good not C because compounds are on reactant side same for D E is good F is no because F2 is usually a gas, not a liquid under standard conditions. I hope this helps! :) Solution In other words, this is asking you how to write a proper delta H reaction for formation. Rules: 1. only one mole on product side... so balance reactant side accordingly to get to this. This may mean putting in fractions that look sort of strange. 2. only elemental forms on product side... no compounds! 3. reactants are in standard states of matter for their respective element (i.e. oxygen should be a gas, not a solid, and iron should be a solid, not a liquid, etc.) So... not A because 2 mol product B is good not C because compounds are on reactant side same for D E is good F is no because F2 is usually a gas, not a liquid under standard conditions. I hope this helps! :).

1. In other words, this is asking you how to write a proper delta H reaction for formation.
Rules:
1. only one mole on product side... so balance reactant side accordingly to get to this. This may
mean putting in fractions that look sort of strange.
2. only elemental forms on product side... no compounds!
3. reactants are in standard states of matter for their respective element (i.e. oxygen should be a
gas, not a solid, and iron should be a solid, not a liquid, etc.)
So... not A because 2 mol product
B is good
not C because compounds are on reactant side
same for D
E is good
F is no because F2 is usually a gas, not a liquid under standard conditions.
I hope this helps! :)
Solution
In other words, this is asking you how to write a proper delta H reaction for formation.
Rules:
1. only one mole on product side... so balance reactant side accordingly to get to this. This may
mean putting in fractions that look sort of strange.
2. only elemental forms on product side... no compounds!
3. reactants are in standard states of matter for their respective element (i.e. oxygen should be a
gas, not a solid, and iron should be a solid, not a liquid, etc.)
So... not A because 2 mol product
B is good

2. not C because compounds are on reactant side
same for D
E is good
F is no because F2 is usually a gas, not a liquid under standard conditions.
I hope this helps! :)