Which of the following contains a coordinate covalent bond? (H...

Question

Which of the following contains a coordinate covalent bond? (Hint: How many covalent bonds would you expect the central atom (underlined/bold) to form?)

a. PbCl₂

b. Cu(NH₃)₄²⁺

c. NH₄⁺

Accepted Answer

Welcome back, everyone. Which of the following contains a Covalin coordinate bond. A hint is to estimate the number of Covalin bonds that the central atom should form. Recall that a Covalin coordinate bond consists of electrons that are we'll say shared electrons from the same atom. So looking at choice one, we have zinc based on its position on the periodic table in group two B means that it's considered a medal Plus flooring being in group seven a are halogen group on the periodic table means it's a non metal. We have the combination of a single zinc atom surrounded by two flooring atoms in which each bond to zinc represents ionic bonds. And so we would rule out choice one since we can see that for each of these bonds, one of the two valence electrons are contributed from zinc and the second would be contributed from flooring the flooring atoms. So we can now move on to choice two in which we have aluminum And chlorine recall that aluminum based on its position on the periodic table in group three a means it's a medal And Chlorine based on its position in our Halogen Group seven A is a nonmetal. Now, we need to look at the compound or of the structure of aluminum chloride. Notice that aluminum, which is less electro negative than chlorine would be our central atoms. So we have two aluminum atoms in the center and we're surrounded by six chlorine atoms. So we have 12345 and six, as we stated, aluminum has three valence electrons and we have two aluminum atoms. So we need to calculate total valence electrons. And seeing that we have four aluminum, two atoms times three valence electrons that would give a contribution of six valence electrons from aluminum. Then for chlorine, we have six chlorine atoms times the Seven valence electrons per each chlorine giving a contribution of 42 electrons. So adding these together, we have total valence electrons of 48 electrons total. So beginning with our aluminum atoms recall that each aluminum atom has a total of three valence electrons. So we would make covalin bonds between aluminum and chlorine where three of the directly attached valence electrons on aluminum are directly attached to aluminum here. Now note that we need an octet for aluminum and it currently has six valence electrons surrounding itself. And so we would say that for chlorine at this position, it's going to use two of its seven valence electrons to form a Covalin bond here to aluminum. And the same thing would occur at this chlorine at this position here. So we can fill in the rest of our structure where we have our three covalin bonds between aluminum and chlorine and then we would fill in the rest of our remaining electrons. So right now, we can count that we've used 2468, 10, 12, 14, 16 of our 48 electrons. So subtracting 16, that leaves us with a balance of 32 valence electrons which we can use as lone pairs to complete the octet of chlorine recognize that each of our chlorine atoms only have a single valence electron attached to themselves. Whereas these two with which had the coordinate Covalin bonds to aluminum have to directly attached or rather three directly attached valence electrons. So we would fill in the rest where we have 246,  aN:aN:000NaN 8, 10 12 14 16 18 2022, 24, 26, 28, 30 and 32 to use up our balance of 32 electrons. So we have zero left and we know that this is the correct structure of aluminum chloride and notice that we've determined that we have to coordinate covalin bonds. So even though this, this compound seems like it's ionic because we have a non metal aluminum bonded to or sorry, a metal aluminum bonded to a non metal chlorine, we have in our structure of aluminum chloride, a structure made up of molecules which share Covalin bonds between each atom and two co coordinate Covalin bonds between chlorine and aluminum. So we can confirm that aluminum chloride does confirm a coordinate Covalin bond. So now moving on to option three, which is carbon monoxide. Recall that carbon based on its position in group four A means that it's a non metal and oxygen based on its position in group six. A means that it's a non metal. So we have a Covalin compound and drawing the structure of carbon monoxide. We have carbon bonded to oxygen. Recall that oxygen has a bonding preference of having two bonds and two lone pairs on itself. And calculating our total valence electrons, we have one atom of carbon multiplied by carbon being in group four A, it's four valence electrons giving a contribution of four valence electrons. And then for oxygen, we have one oxygen atom multiplied by its six valence electrons, citizen group six a contributing six valence electrons total. So taking our total valence electrons, we would have 10 valence electrons for our structure. We're utilizing the bonding preference of oxygen. We've used a total of 2468 of our 10 valence electrons leaving us with a balance of two. So we would place those two electrons as a lone pair on carbon and notice that we would only have 246 electrons around carbon and recall that carbon does need an octet. So in this case, we would take one of our lone pairs from oxygen and use it to form a coordinate Covalin bond between oxygen to carbon. So we would have the resultant structure where we now have carbon with a lone pair and a triple bond to oxygen where oxygen has also one lone pair. And this first top bond here and we'll make our highlighter smaller. This first top bond here represents our coordinate covalin bond. So this would be also a correct answer. Choice, meaning we can confirm that choice three is correct for carbon monoxide. So to complete this example, our final answer is going to be choices two and three as examples of showing coordinate Covalin bonds. So I hope this helped and let us know if you have any questions.

Which of the following contains a coordinate covalent bond? (Hint: How many covalent bonds would you expect the central atom (underlined/bold) to form?)
a. PbCl₂
b. Cu(NH₃)₄²⁺
c. NH₄⁺

Key Concepts

Covalent Bonding

Coordinate Covalent Bond

Central Atom and Valency

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