A copper wire having a mass of 2.196 g was allowed to react with ...

Question

A copper wire having a mass of 2.196 g was allowed to react with an excess of sulfur. The excess sulfur was then burned, yielding SO2 gas. The mass of the copper sulfide produced was 2.748 g.
(c) Calculate the number of copper ions per cubic centimeter if the density of the copper sulfide is 5.6 g/cm3.

Accepted Answer

Hello. Everyone in this video. We're trying to determine the number of every three plus ions per cubic centimeter. It were given the density of the F E 203. And also given the amount of sample of iron that reacts with the excess 02. And were given how much of the F E 203 is formed. So let's first kind of write out the key information that we're given. So the density Is given to us being 5.25 units being g per centimeter. Cute. And then the molar mass Of FE 203 is equal to 1 59.687 units being g per mole. Alright, let's also realize, let's see here the avocados number if we recall are for Guardo's number is equal to So we have 6.22 times 10 to the 23rd F. E. Or just any ions or atoms per mole. Okay. All right. So this is kind of the key information here that were written in black. Now let's go ahead and start with the dimension analysis. Starting off with our density, We have 5.25 g per centimeter cubed. And of course it's in regards to FE 203. Let's go ahead and add that. Alright, so now we're going from grams of F E two or 32 moles of this. So we can go ahead and use the molar mass. So in the bottom I'll go ahead and put my grams which is 159.687 g of F E 203 for every one mole of F E 203. All right, so we can cancel the units of grams. Now we have the moles of F E 203. We want to go ahead and do or use the multi mole ratio four moles of f E 203 with molds of the Catalan. So we can see from the compound itself that for every one mole of F E 203, two moles of FE three plus is needed. Then using avocados number, we can get the number of ions that's needed. So for every one mole of F E three plus we have 6.22 times 10 to the 23rd power of F E three ions. Alright, we can go ahead now to see that the molds of F E three plus will cancel leaving us with the units of while I was on top. It would be F E three plus ions. Alright, so we can see once we put everything into a calculator we will get the numerical value of 3.95 times 10 to the 22nd power and units being R F E three plus ions of course per centimeter cubed because we never canceled this out and then our for an answer is just going to be this and highlighted. All right, thank you all so much for watching and hopefully this made sense

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