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potassium sorbate and they give us its formula right over here has a molar mass of 150 grams per mole they put this decimal here to show us that these are actually three significant figures even the zero is a significant digit here is commonly added to diet soft drinks as a preservative a stock solution of potassium sorbate dissolved it's an aqueous solution here of known concentration must be prepared a student tight rates 45 milliliters of the stock solution with 1.25 molar hydrochloric acid using both an indicator and a pH meter the value of ka for sorbic acid is 1.7 times 10 to the negative fifth all right so let's tackle this piece by piece write the net ionic equation for the reaction between potassium sorbate and hydrochloric acid all right so first I'll just write the ionic equation and then we'll I'll write the net ionic equation and hopefully you'll see the difference so ionic ionic equation and the way we think about ionic equations is we think about well if these are dissolved in water it's an aqueous solution these are going to disassociate into their into ions and so we would write that out on both the on both the reactant and the product side so the potassium sorbate we can write that as it's going to be a potassium ion dissolved in aqueous solution plus the c6h 7:02 this is also going to be an ion dissolved in the aqueous solution plus the hydrochloric acid will dissolve so you have the hydrogen proton dissolved in the aqueous solution plus the chloride ion or an ion I guess we could say it so that's going to be in our aqueous solution and then they react what happens well you're going to have the c6h 7:02 react with the hydrogen proton to get to sorbic acid so you're going to have sorbic acid h c 6h this is a six here H seven Oh - that's the sorbic acid it's going to be in an aqueous solution so I took care so far of that and that and then you're going to have and then you're going to have your potassium ions your potassium ions and your chloride ions it's going to be just like that so this right over here is the ionic equation not the net ionic equation I have the ions on the reaction on the reactant side and then on the product side right over here and did I yep I included everything now when you do the net ionic reaction you can imagine what's going to happen here I have potassium ions on the Left I have potassium ions on the right I could net them out on both sides so let's net them out on both sides I have chloride ions on the Left I've chloride ions on the right I can net them out on both sides and then I can write the net ionic equation so the net ionic equation net ionic equation is going to be well I have my c 6h 7:02 ion dissolved in an aqueous solution you combine that with the hydrogen proton dissolved in the aqueous solution and it's going to it's going to give us sorbic acid h c 6h 7:02 in our aqueous solution so there you have it that is the net ionic equation