Alright, i wont go into detail with all the calculations, but here is basicly what you need to do with all this data and equations. first of all, we need to understand when to use these data (energies). so we will have to look at the chemical equation ( the overall equation that we are trying to obtain the heat of formation for). Use Hess\'s Law, flip the second reaction around, combine it and you get the overall reaction: Sr + H2O ---> SrO + H2 the delta H of this reaction is : 496KJ/mol Now to find the answer for b) Born Haber Cycle. Sr(s) + H2O(l) ---> SrO(s) + H2(g) start with Sr(s), we need to make it into a gas, so we need to take into account the heat of sublimation of Sr, which is one of the data you got from data table. so: (instead of writing delta H everytime, im just gonna write Hf for Heat of formation) Hf of SrO = Hs(heat of sublimation) of Sr + ..... ok now that we have Sr in gas state, we need to make it into an ion. therefore we need to take IE (ionization energy ) 1 into account. that makes Sr-, but we need Sr2+ so we need to add IE2 as well. Hf of SrO = Hs +IE1+ IE2 +... ok so we got Sr in the desired state, now we need to treat H2O(l). Lets start by making it a gas.we want O2 and H2. so if it takes -286Kj/mol to form water, it must take 286Kj/mol to break down water. Hf of SrO = Hs +IE1+ IE2 + Hf(water) +... Now we want to made O2 into O atoms, we have to break bonds, so we need to take into account bond energy of oxygen. Hf of SrO = Hs +IE1+ IE2 + Hf(water) + BE(oxygen)+... Once we have O atoms, we want it to become O- be applying the AE1 Hf of SrO = Hs +IE1+ IE2 + Hf(water) + BE(oxygen)+ AE1 finally once we get all that we want, the SrO will be in gas form so we need to crystallize it. Hf of SrO = Hs +IE1+ IE2 + Hf(water) + BE(oxygen)+ Lattice Energy plug in your values, beware of balance equations sometimes you will have to divide one of you energies by half or times it by 4 accordingly to your balanced equations. Solution Alright, i wont go into detail with all the calculations, but here is basicly what you need to do with all this data and equations. first of all, we need to understand when to use these data (energies). so we will have to look at the chemical equation ( the overall equation that we are trying to obtain the heat of formation for). Use Hess\'s Law, flip the second reaction around, combine it and you get the overall reaction: Sr + H2O ---> SrO + H2 the delta H of this reaction is : 496KJ/mol Now to find the answer for b) Born Haber Cycle. Sr(s) + H2O(l) ---> SrO(s) + H2(g) start with Sr(s), we need to make it into a gas, so we need to take into account the heat of sublimation of Sr, which is one of the data you got from data table. so: (instead of writing delta H everytime, im just gonna write Hf for Heat of formation) Hf of SrO = Hs(heat of sublimation) of Sr + ..... ok now that we have Sr in gas state, we need to make it into an ion. therefore we need to take IE (ionization energy ) 1 into account. tha.

1. Alright, i wont go into detail with all the calculations, but here is basicly what you
need to do with all this data and equations. first of all, we need to understand when to use these
data (energies). so we will have to look at the chemical equation ( the overall equation that we
are trying to obtain the heat of formation for). Use Hess's Law, flip the second reaction around,
combine it and you get the overall reaction: Sr + H2O ---> SrO + H2 the delta H of this reaction
is : 496KJ/mol Now to find the answer for b) Born Haber Cycle. Sr(s) + H2O(l) ---> SrO(s) +
H2(g) start with Sr(s), we need to make it into a gas, so we need to take into account the heat of
sublimation of Sr, which is one of the data you got from data table. so: (instead of writing delta
H everytime, im just gonna write Hf for Heat of formation) Hf of SrO = Hs(heat of sublimation)
of Sr + ..... ok now that we have Sr in gas state, we need to make it into an ion. therefore we
need to take IE (ionization energy ) 1 into account. that makes Sr-, but we need Sr2+ so we need
to add IE2 as well. Hf of SrO = Hs +IE1+ IE2 +... ok so we got Sr in the desired state, now we
need to treat H2O(l). Lets start by making it a gas.we want O2 and H2. so if it takes -286Kj/mol
to form water, it must take 286Kj/mol to break down water. Hf of SrO = Hs +IE1+ IE2 +
Hf(water) +... Now we want to made O2 into O atoms, we have to break bonds, so we need to
take into account bond energy of oxygen. Hf of SrO = Hs +IE1+ IE2 + Hf(water) +
BE(oxygen)+... Once we have O atoms, we want it to become O- be applying the AE1 Hf of
SrO = Hs +IE1+ IE2 + Hf(water) + BE(oxygen)+ AE1 finally once we get all that we want, the
SrO will be in gas form so we need to crystallize it. Hf of SrO = Hs +IE1+ IE2 + Hf(water) +
BE(oxygen)+ Lattice Energy plug in your values, beware of balance equations sometimes you
will have to divide one of you energies by half or times it by 4 accordingly to your balanced
equations.
Solution
Alright, i wont go into detail with all the calculations, but here is basicly what you
need to do with all this data and equations. first of all, we need to understand when to use these
data (energies). so we will have to look at the chemical equation ( the overall equation that we
are trying to obtain the heat of formation for). Use Hess's Law, flip the second reaction around,
combine it and you get the overall reaction: Sr + H2O ---> SrO + H2 the delta H of this reaction
is : 496KJ/mol Now to find the answer for b) Born Haber Cycle. Sr(s) + H2O(l) ---> SrO(s) +
H2(g) start with Sr(s), we need to make it into a gas, so we need to take into account the heat of
sublimation of Sr, which is one of the data you got from data table. so: (instead of writing delta
H everytime, im just gonna write Hf for Heat of formation) Hf of SrO = Hs(heat of sublimation)
of Sr + ..... ok now that we have Sr in gas state, we need to make it into an ion. therefore we
need to take IE (ionization energy ) 1 into account. that makes Sr-, but we need Sr2+ so we need
to add IE2 as well. Hf of SrO = Hs +IE1+ IE2 +... ok so we got Sr in the desired state, now we

2. need to treat H2O(l). Lets start by making it a gas.we want O2 and H2. so if it takes -286Kj/mol
to form water, it must take 286Kj/mol to break down water. Hf of SrO = Hs +IE1+ IE2 +
Hf(water) +... Now we want to made O2 into O atoms, we have to break bonds, so we need to
take into account bond energy of oxygen. Hf of SrO = Hs +IE1+ IE2 + Hf(water) +
BE(oxygen)+... Once we have O atoms, we want it to become O- be applying the AE1 Hf of
SrO = Hs +IE1+ IE2 + Hf(water) + BE(oxygen)+ AE1 finally once we get all that we want, the
SrO will be in gas form so we need to crystallize it. Hf of SrO = Hs +IE1+ IE2 + Hf(water) +
BE(oxygen)+ Lattice Energy plug in your values, beware of balance equations sometimes you
will have to divide one of you energies by half or times it by 4 accordingly to your balanced
equations.