Which of the following is true of electrolytes

Question

Accepted Answer

hey everyone in this example, we need to choose the true statement. So looking at statement a it says a weak acid or base is considered a weak electrolyte because the solution contains mostly ionized particles. So we want to pay attention to two terms here, The first being ionized particles. And that's referring to our solution containing cat ions, which we recall have a positive charge as well as our solution containing and ions which we recall having negative charge. Next. We want to pay attention to the term electrolyte. And specifically this question states that we have a weak electrolyte. So on the other hand, we can define what a strong electrolyte is. And when we think of a strong electrolyte, it's going to be all soluble ionic compounds. Now in this case we have to determine the eligibility rules for our given ionic compound. And if the ionic compound based on the rules is soluble, it's going to fully dissociate to form a high concentration of ionized particles. And so we're going to form Canadians and an ions as products. However, because we have in this question or in this statement a weak electrolyte, we're going to do the exact opposite. In that case our solution is going to contain a small amount of ionized particles or a lower concentration of ionized particles because of the fact that weak electrolytes do not fully disassociate like strong electrolytes do. So they do not fully dissociate into ions. And so we would correct this statement to make it true by changing this term weak hair too strong and changing the week in front of acid or base too strong as well because we form a strong electrolyte from strong acids or strong basis. So A is not true. We roll it out. Moving onto Choice B, a solution that contains mostly partially ionized molecules is considered a strong electrolyte. Again, if above we recalled that weak electrolytes do not fully dissociate into ions. Then that means that statement B is talking about a weak electrolyte here. So we would correct the term strong two weak because we have formed partially ionized molecules, which is exactly what weak electrolytes form. They don't fully dissociated ions. So they're ions are partially ionized in solution. So B is also false. We can rule it out as a choice. Next we have C. Which says that a strong electrolyte is a substance that completely ionized in solution. So if it completely ionized in solution we have a high concentration of our scallions and and ions that are formed. And so this is going to definitely be a true statement, we can consider C. A good choice. Moving on to statement D weak electrolytes are very reactive substances. So when it comes to reactivity of electrolytes, we're gonna want to recall two things. The first being the stability of the conjugate acid or conjugate base produced by our electrolyte whether it's strong or weak. We're going to always want to consider how stable their conjugate acid or their conjugate base is as a product and we would determine stability from their electoral negativity. So we would determine the stability of our conjugate acid or base from the election negativity and the formal charge on the central atom. We also would want to think of the ionic character of our given electrolyte. So, for example, let's go ahead and just write out the compound ammonia. So if we go ahead and dissolve that in solution, we're going to want to first before we can predict our products label our ammonia as either a acid or base. And we should recall that ammonia is a weak base. We know that because it's not on our list of memorized strong basis. So because ammonia is a weak base, it's going to be therefore a weak electrolyte. Now to determine the reactivity and predict our products. We're going to want to because it's a base recall that bases are going to be accepting a proton from water. So a proton from water is going to go ahead and make a bond with the lone pair on our nitrogen because we have listed ammonia as a base and so it's going to be a proton except er And so in doing so when our proton from water goes ahead and forms a bond with the nitrogen in ammonia, we form our conjugate acid of our weak base ammonia NH four with a positive charge. So we formed an ionized particle in this case a cat on here and again, this is our Conjugate acid of our NH three ammonia. And because water has donated a proton acting as an acid, it's going to form the product hydroxide, o H minus. Now. We also want to go ahead and now consider the stability of this conjugate acid. So what we would consider is our electro negativity difference between the two atoms and our ammonia. I on here, we're going to consider that nitrogen. Because we recall that our electro negativity difference is increasing from the bottom towards the right of our periodic tables, nitrogen is going to be more electro negative than the hydrogen atom in this compound. And so it's going to have a partially negative charge in our labeling here now because the hydrogen is a lot less electro negative based on the electro negativity trend, it's going to have a slightly positive charge. And we should recall that anything with a slightly negative charge, like the nitrogen in this example, is going to be pulling the electrons more towards itself. So, in NH four plus, the electrons that nitrogen shares within this compound are going to be pulled more closely to the nitrogen. However, because of that, it makes it hard for nitrogen to want to support having this plus charge on its um in its compound here in this compound. So it would rather support a negative charge since it's more electro negative. And so that would mean that this atom here where this compound is going to be very unstable. We can also consider the formal charge of NH four plus and specifically the formal charge of the central atom here, which is our nitrogen or are more electro negative atom nitrogen. So when we calculate the formal charge of nitrogen, we're going to want to recall that it's going to be valence five minus the directly attached electrons in the structure of ammonia to the nitrogen. And so as far as our structure of ammonia, We're gonna be surrounded by four hydrogen. And we want to recall that within a bond, we have two electrons but we only want to count the electrons that are directly attached to the nitrogen. So that would be 123 and four. And so in this case because we have these four directly attached electrons, we would just take five minus four, Which gives us plus one. And so again, because our central atom is electro negative and would rather support a negative formal charge where we have a positive formal charge in ammonia, we would say that it's unstable. It's an unstable conjugate acid. And so therefore we would say that overall this unstable conjugate acid produced from our given weak electrolyte is going to be poorly reactive. It's only going to be slightly reactive, forming a small amount of our ammonia cat ion as a product. And so we can rule out d because we would say that this really depends, it depends specifically on what we've outlined before. over here on the right, so to complete this example, the only correct choice is going to be choice C state stating a strong electrolyte is a substance that completely ionized in solution. So I hope that everything we reviewed was clear. If you have any questions, leave them down below, and I'll see everyone in the next practice video.

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Which of the following is true of electrolytes

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