Arrange the following oxides in order of increasing covalent character: B2O3, BeO, CO2, Li2O, N2O5.

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Hi, everybody. Let's take a look at our next problem. Arrange the oxides in increasing order from least covalent to most covalent. And the oxides we have are so two or sulfur oxide A S 205 or arsenic oxide cao or calcium oxide, G A 203 or gallium oxide and RB 20 or rubidium oxide. So what is it that makes an oxide more or less covalent? Well, we recall that oxides can be formed. They are binary compounds where oxygen has its minus two oxidation state and they can be formed when oxygen combines with either a metal or a non metal. We also can have oxides with those elements in the middle. But for purposes of looking at the extremes to be able to rank these, we want to think about the two metal versus non metal metal. So metal oxides, what characterizes a metal, they give up their electrons. So metal oxides will be ionic compounds, the metal will completely give up its electrons to oxygen which is happy to accept them and you have an ionic compound. So most ionic least com covalent are the most metallic elements combined with the oxygen in non metal oxides, nonmetals are not going to give up their electrons completely, they're going to share their electrons. So these will be covalent compounds. So we want to put these in order from least covalent to most covalent. So that would be from most to least metallic in character for the element the oxygen is combined with. So we need to look at our other elements and think about their periodic trends to put them in order. So let's think about our periodic table. Well, it's pretty simple to remember that as we go from left to write, we're going from most to least metallic because obviously our elements on the very left have just the one or two electrons in their outer shell and are much more likely to give them up. So from left to right, we're becoming less metallic. Now, we need to think about our rows top to bottom. Well as the elements be because as the atoms become larger, their electrons are further away, then therefore, are easy to give up. So if we're going from most to least metallic, going from bottom to top, so as we go down the rows, we increase the metallic character. So therefore, our elements on the bottom left of the periodic table will be the most metallic, our elements on the top, right, the least metallic. So I've drawn a diagonal line from bottom left to top, right, to help us remember the order we want our elements to go in. Well, now let's think about it. Let's look at our elements and see where they go. I'm gonna draw a little grid to help us sort of put them in order rather than drawing a whole periodic table just looking at rows and columns here. So I've just drawn four horizontal lines for right now, we'll just sort of place them left to right again. We've just got our five compounds here. So we don't need to have a lot of detail. Just sort of generally a visual picture we do to keep them straight. So sulfur oxide, sulfur is in column six A, it's in row three. So we're pretty far over to the right. I'm going to make my top row row three for now. I can add on more if I need to. So put sulfur up here, it's pretty far to the top right. Uh Our next element is arsenic. Arsenic is in column five A row four. So I'm going to put it a little to the left of sulfur and one row down. So I'm going to label my dot I put a little dot I'm gonna label them sulfur and arsenic. My next compound being calcium, calcium we can recall is in column two A, it's down in row four also. So same row as arsenic, but way over to the left. Put a little dot there and label that calcium. Now we move on to gallium it's in column three, a row four as well. So it's over on the right side still in that same row as calcium and arsenic. But in between them, there is gallium and finally, rubidium, rubidium's way over in column one a down in row five. So definitely the bottom left here, there's our rubidium. So again, we are looking for this trend going bottom left to top, right. So our least covalent, we would look in the bottom left and that will be rubidium oxide. Well, we only have one answer choice that has rubidium oxide first. And that's choice. D So on a test, I would just pick that and move right on because we know we have the correct answer just by eliminating the other three, none of them have rubidium oxide first. And that's a very clear cut choice for our least covalent oxide. Just to be thorough, we'll make sure the others are in the correct order. We now have three elements in the next row up row four. So we would be going from left to right, becoming less metallic. So calcium's the farthest left. So calcium oxide will be next gallium in the middle there. So gallium oxide next arsenic, the farthest to the right. So arum oxide next. So those three are in the correct order calcium gallium arsenic. And finally, we've got the sulfur oxide Sulfurs up here, farthest to the right and farthest to the top sulfur oxide. Definitely the most covalent. So we definitely have our answer of choice d arranging the oxides in increasing order from least covalent to most covalent rubidium oxide, calcium oxide gallium oxide, arsenic oxide, and sulfur oxide. See you in the next video.

Arrange the following oxides in order of increasing covalent character: B2O3, BeO, CO2, Li2O, N2O5.

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Key Concepts

Covalent Character

Electronegativity

Oxide Types