List the following gas-phase ion pairs in order of the quantity o...

Question

List the following gas-phase ion pairs in order of the quantity of
energy released when they form from separated gas-phase ions.
List the pair that releases the least energy first. Na+ F - , Mg2 + F - ,
Na+O2 - , Mg2 +O2 - , Al3 +O2 - .

Accepted Answer

Hey everyone in this example, we're told that the combination of Catalans and ann ions in the gas phase releases a lot of energy due to the stabilization of ions. We need to arrange the following gas phase ion pairs here and ascending order based on how much energy they release when they form. So we're going to be arranging them from lowest two highest lattice energy or lattice energy. So what we need to do is go ahead and recall the fact that we have lattice energy that will be increasing with charge and will be decreasing with ion distance. And when we're referring to the ion distance, we're going to recall our trend on our periodic table for atomic radius, which we should recall is going to increase as we go from the top right to the bottom left of our periodic table. I'm sorry, this says increasing here. And so we should recall that ions follow the same trend as atomic radius. So we're going to have larger ions when we go from the top right towards the bottom left of our periodic tables. And so as we said, we want to go ahead and listings in ascending order. So we're going to find the smallest atomic ready out of all of the given ion gas phase pairs. And because again we said that an increased charge corresponds to an increased lattice energy, we're going to list the ion gas pairs with the higher charges towards the end of our ordering because they will correspond to having the largest lattice energy released. So to begin our order of ascension, we want to find the gas phase ion pair that has the lowest amount of energy released. And so we want to find the ion gas phase pair with the lowest charges. And as you can see, we have only a plus one and minus one charge with the lithium carry on and bromide an ion pair compared to the rest of our charges. We at least have a two plus two minus charge associated with the other pairs. So we're gonna list lithium, Cagayan and bromide, anna. And as our first order for the lowest lattice energy released by this atom or buy this pair next up in our ordering, we want to find the next lowest charges associated with the given pairs. So again, we're given the potassium plus one carry on. And the sulfide to minus an ion which are the next lowest charges in our given list of gas phase pairs. So we would say that this gas phase pair has a largest or a larger amount of lattice energy released between the two ions and it's larger in comparison to the lithium ion and bromide an ion because we have a two minus charge on our sulfide an ion. And so that's a greater charge, meaning this has a larger amount of energy released for the pair. We also would agree that potassium is a much larger carry on compared to lithium because it's lower on our periodic table, which we would recognize it in period four of our periodic tables in group one a and lithium is only in period two, which is further up meaning it has a smaller atomic radius. So this would definitely make sense listing second in our ordering. However, with an even larger amount of lattice energy released, we would then list our calcium two plus catalon and the chlorine or chloride. And I on here due to the fact that a more positive ion charge being two plus on our calcium Catalan corresponds to a larger lattice energy value released from the ion pair here. So we would list this next because it releases an even larger amount of energy than this pair we released before. That we listed before next we want to go ahead and recognize that we have an even greater amount of energy released from the pair. Be a two plus and 02 minus due to the fact that we do have these two plus and two minus catalon and an eye on charges compared to just having a two plus and minus one and in charge. So, we have an increased value in both are an ion and caddy on charges corresponding to an increase in our lattice energy for this pair here. And so this pair here releases even more energy compared to the calcium, Canadian and chloride. An ion. And lastly, that leaves us with our largest charge here associated with aluminum and the oxide, an ion with an 02 minus charge which releases the greatest amount of lattice energy within the pair here. Due to the fact that we have a three plus and two minus an ion charge paired up for this gas phase ion pair. And so to complete this example, we have properly listed the highest lattice energy released versus our lowest amount of lattice energy released. And so this will be our final answer here to complete this example corresponding with choice B on our multiple choice. So I hope that everything I went through is clear. If you have any questions, please leave them down below and I will see everyone in the next practice video.

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