Which compound is a solid at room temperature? (LO 7.8)
(a) H2O
(...

Question

Which compound is a solid at room temperature? (LO 7.8)
(a) H2O
(b) Na2S 
(c) SO3 
(d) Cl2

Accepted Answer

welcome back everyone each of the molecules below exists as a solid at room temperature except one identify the exemption. So before we analyze each compound, we want to recognize that ionic compounds are going to be solid at room temp. And so we need to determine out of these given compounds which would be ionic compounds beginning with lithium bromide, analyzing our adam lithium first, we recognize that based on its position in group two A. Or sorry in group one A. On the periodic table, it's going to be considered a medal and it's bonded with bromine, which we recognize is in our halogen group seven A. On the periodic table, which makes it considered a non metal. And because we have the pairing of a metal and a nonmetal, we would recognize that lithium bromide is an ionic compound and therefore it does exist as a solid at room temperature. So we can rule out lithium bromide choice A. Because we want to find the exemption here. Moving on to our second choice, we have hydro biotic acid, H. I where we have Hydrogen, which we find in group one a. On the periodic table, meaning it's considered Our only exception from group one a. as a nonmetal where iodine we find on our periodic table in our halogen group seven A. So it's also a non metal like bromine. And again, or rather in this case we have two non metals paired with one another, meaning that this is a molecular or covalin compound. And so it won't exist as a solid at room temperature. So we're going to keep choice B as an option since it could be an example of an exception to complete this problem. So moving on to choice C. We have magnesium chloride beginning with magnesium based on its position in Group two A. It's going to be considered a medal. And then for chlorine we recognized based on its position. Also in Group seven A. Are halogen group chlorine is a non metal. So we have the pairing of a metal and a nonmetal meaning that this is indeed an ionic compound and will exist as a solid at room temperature. So we can rule out choice C. Magnesium, die chloride. Moving onto choice D. We have iron oxide where iron we recognize based on its position in our transition metal D. Block is considered a metal and it's bonded with oxygen, which we recall it in group six day of our periodic table, meaning oxygen is a non will say non metal here. So again, we have the pairing of a metal and a nonmetal meaning that this is an ionic compound. So it will exist as a solid at room temperature. And lastly, we can rule out choice D. And move onto choice B. Where we have our formula potassium nitride. We're beginning with And sorry about that. Beginning with potassium based on its position in group one A on the periodic table, it's going to be considered a metal bonded with nitrogen, which we recognize is located in Group five A on the periodic table and is considered a non metal, meaning because we have the pairing of again, a metal and a nonmetal potassium nitrite is an ionic compound and will exist as a solid at room temperature. And so the only exception that we found was choice B. Hydro acetic acid, which does not exist as a solid at room temperature because it's considered a molecular or covalin compound B is our final answer. To complete this example. I hope everything I explained was clear. If you have any questions, please leave them down below and I'll see everyone in the next practice video.

Watch next