An aqueous solution of a cation (represented as blue spheres in the diagram) is allowed to mix with a solution of an anion (represented as green spheres) and the following result is obtained:
Which combinations of cation and anion, chosen from the following lists, are compatible with the observed results? Explain.
Cations: Na⁺, Ca²⁺, Ag⁺, Ni²⁺
Anions: Cl⁻, CO₂^3–, CrO₄^2–, NO₃^–

Question

An aqueous solution of a cation (represented as blue spheres in the diagram) is allowed to mix with a solution of an anion (represented as green spheres) and the following result is obtained:

Which combinations of cation and anion, chosen from the following lists, are compatible with the observed results? Explain.

Cations: Na⁺, Ca²⁺, Ag⁺, Ni²⁺

Anions: Cl⁻, CO₂^3–, CrO₄^2–, NO₃^–

Accepted Answer

Welcome back everyone. Aquarius solutions of Acadian in green and an an ion and red are mixed together resulting in the formation of a solid. Identify the ions that can possibly cause the reaction. Beginning with choice A, we have our sodium plus one carry on and our hydroxide O H minus an eye on. We're going to need to cross the charges of these two ions to form our product and A O H for sodium hydroxide. So to get to our answer, we want to recall our selling ability rules And in this case recognized that sodium a part of our product is a group one a Adam And recall that all group one, a Adams or compounds will say are soluble. And because sodium hydroxide is a group one, a compound, we're going to give it the label, a cue for a quiz, meaning that it dissolves in water, so it's soluble and will not be a solid. So ruling out choice A, we're going to move onto choice B where we have our strontium two plus carry on and our oxide 02 minus an eye on crossing the charges will give us S R O where we have strontium oxide as the product. We want to recall our Celje bility rule for oxides and recall that all oxides are going to be insoluble except when paired with Atoms such as Group one A atoms or group to a atoms, including calcium barium and strontium. And we do have our oxide paired with strontium in this case. So this is our exception as a soluble oxide and we would give it also the label A Q and rule out choice B. We want only our answer to be an insoluble solid product. Looking at choice. See, we have our silver A G plus catalon and our bromide B R minus an eye on. When we cross the charges, we get a G B R for silver bromide where we want to recall that bro mean located in group seven A is a halogen. And so it's going to be a Hey lied and we recall our cell viability rule for hey leads which states that all hey, lights are soluble except when paired with Adams such as mercury, silver or lead. In this case, we have our hey lead bromine paired with silver. So this is an insoluble. Hey lied and we would give it the label S for solid. So see, looks like a correct answer choice so far. But let's keep considering and move on to choice T. In choice D we have our SN two plus 10 catalon and R S 042 minus sulfate an ion crossing. The charges here gives us S N S 04 for 10 sulfate. And we want to recall our ability rule for sulfates. Recall that all sulfates are soluble Except one paired with Adams such as calcium, barium strontium, mercury HD, silver or lead PB. We do not have any of those exceptions paired in our product, we have 10 sulfate. And so this is going to be a soluble sulfate and gets the label AQ, meaning we can rule out choice D because again, it produced a soluble product. So our only correct answer is going to be choice C which has the ions A G plus and B R minus that can cause the reaction that is depicted in our illustration for this prompt. So I hope this made sense and let us know if you have any questions.

Verified video answer for a similar problem:

Key Concepts

Ionic Compounds

Solubility Rules

Precipitation Reactions