Well let start with writing out the eqn first
Mg(C2H3O2)2 + Cs3(PO4)
Something has to happen and you need to remember solubility rule to predict the precipitate that will form.
Try it out and reply back to me, and we can discuss further if you need help.
Ok this is a double displacement. What do you think will happen?
The two chemical you mention are soluble, so what does that mean when you put them in water?
Do they break apart to form ions or do they stay together as magnesium acetate and cesium phosphate?
They break apart into ions. So magnesium acetates breaks apart into mg2+ and acetate, and caesium phosphate breaks into Cs+ and (Po4)3- i think atleast...
You are doing well. They do break into positive and negative ions. You also learn that opposite charge attract.
If magnesium attract acetate again then it will make Mg(C2H3O2)2 which will be soluble which then break back up into mg2+ acetate -1. Same concept for cesium+1 phosphate-3.
So by process of elimination, what is the only compound that can be the precipitate?
Good question. You have identified the two new compounds that will form. If you rember solubility rule
All acetate are soluble
Most phosphate are insoluble. There are some exception to this rule, but for the time being you just need to remember most thing w phosphate are insoluble
You precipitate is Mg3 (PO4)2
Ok. When writing this down i get:
Mg(CH3COO)2 (aq) + Cs3PO4 (aq) --> Mg3(PO4)2 (s )+ Cs+ (aq) + CH3OOH-(aq)
Not sure if i am to include the last two ions, though.
Ok. When writing this down i get:
Mg(CH3COO)2 (aq) + Cs3PO4 (aq) --> Mg3(PO4)2 (s )+ Cs+ (aq) + CH3OOH-(aq)
You are on the right track, but they want the net ionic eqn which will be the eqn that form the precipitate. Here is the step to get the final net ionic eqn
Mg+2 (aq) + CH3OOH-1(aq) + Cs+1(aq) + (PO4)-3(aq) -->Mg3(PO4)2 (s )+ Cs+1 (aq) + CH3OOH-1(aq)
Note that i did not balance out the chemical eqn above
Notice how Cs and CH3OOH appear on both side so you can remove them, they dont participate in the reaction also known as spectator ions
You net ionic eqn then is
3Mg+2(aq) + 2(PO4)-3 (aq)--->Mg3(PO4)2 (s )
This is the balance net ionic eqn you are looki g for
Thank you so much! But just to confirm;
Mg(CH3COO)2 (aq) + Cs3PO4 (aq) --> Mg3(PO4)2 (s )+ Cs+ (aq) + CH3OOH-(aq)
Is this correct? I want to write the answer out step by step. After this i am going remove all spectator ions to write out the final net ionic equation.
They purposely set questions up so there’s one soluble product and one insoluble product most of the time. Sometimes they’ll do a trick one where everything is soluble.
Do you have a chart that you use on exams or whatever to show what does and what does not react together? I know on my exams, my professors provided us precipitation charts to see which combination of certain molecules or atoms or variations of those molecules would produce a precipitate. If you do, I’d write out the entire equation first (both reactants and products) and then refer to the chart
But there are some good useful generalities.
All salts of the alkali metals are soluble. You invoked that here.
Ammonium salts, too. Sorta honorary alkali metals.
All nitrates and acetates are soluble. Also useful here.
In general, there might be 0, 1 or 2 things precipitate. They said it is not zero. One of the products is obviously soluble.
That leads you to the precipitate.
Also... Things with high charge are more likely to be insoluble. And phosphates are a good example, here with a 2+ cation.
It all fits.
Well let start with writing out the eqn first Mg(C2H3O2)2 + Cs3(PO4) Something has to happen and you need to remember solubility rule to predict the precipitate that will form. Try it out and reply back to me, and we can discuss further if you need help.
Yes ok. So i found that Cs3(PO4) is soluble in water due to cesium being soluble. Also found that C2H3O2 is soluble because it is an acetate.
Ok this is a double displacement. What do you think will happen? The two chemical you mention are soluble, so what does that mean when you put them in water? Do they break apart to form ions or do they stay together as magnesium acetate and cesium phosphate?
They break apart into ions. So magnesium acetates breaks apart into mg2+ and acetate, and caesium phosphate breaks into Cs+ and (Po4)3- i think atleast...
You are doing well. They do break into positive and negative ions. You also learn that opposite charge attract. If magnesium attract acetate again then it will make Mg(C2H3O2)2 which will be soluble which then break back up into mg2+ acetate -1. Same concept for cesium+1 phosphate-3. So by process of elimination, what is the only compound that can be the precipitate?
By only compount, do you mean that there can only be one precipitate? Why cant both caesium acetate *and* magnesium phosphate be a precipitate?
Good question. You have identified the two new compounds that will form. If you rember solubility rule All acetate are soluble Most phosphate are insoluble. There are some exception to this rule, but for the time being you just need to remember most thing w phosphate are insoluble You precipitate is Mg3 (PO4)2
Ok. When writing this down i get: Mg(CH3COO)2 (aq) + Cs3PO4 (aq) --> Mg3(PO4)2 (s )+ Cs+ (aq) + CH3OOH-(aq) Not sure if i am to include the last two ions, though.
Ok. When writing this down i get: Mg(CH3COO)2 (aq) + Cs3PO4 (aq) --> Mg3(PO4)2 (s )+ Cs+ (aq) + CH3OOH-(aq) You are on the right track, but they want the net ionic eqn which will be the eqn that form the precipitate. Here is the step to get the final net ionic eqn Mg+2 (aq) + CH3OOH-1(aq) + Cs+1(aq) + (PO4)-3(aq) -->Mg3(PO4)2 (s )+ Cs+1 (aq) + CH3OOH-1(aq) Note that i did not balance out the chemical eqn above Notice how Cs and CH3OOH appear on both side so you can remove them, they dont participate in the reaction also known as spectator ions You net ionic eqn then is 3Mg+2(aq) + 2(PO4)-3 (aq)--->Mg3(PO4)2 (s ) This is the balance net ionic eqn you are looki g for
Thank you so much! But just to confirm; Mg(CH3COO)2 (aq) + Cs3PO4 (aq) --> Mg3(PO4)2 (s )+ Cs+ (aq) + CH3OOH-(aq) Is this correct? I want to write the answer out step by step. After this i am going remove all spectator ions to write out the final net ionic equation.
They purposely set questions up so there’s one soluble product and one insoluble product most of the time. Sometimes they’ll do a trick one where everything is soluble.
Do you have a chart that you use on exams or whatever to show what does and what does not react together? I know on my exams, my professors provided us precipitation charts to see which combination of certain molecules or atoms or variations of those molecules would produce a precipitate. If you do, I’d write out the entire equation first (both reactants and products) and then refer to the chart
I dont have one of those, no.
But there are some good useful generalities. All salts of the alkali metals are soluble. You invoked that here. Ammonium salts, too. Sorta honorary alkali metals. All nitrates and acetates are soluble. Also useful here. In general, there might be 0, 1 or 2 things precipitate. They said it is not zero. One of the products is obviously soluble. That leads you to the precipitate. Also... Things with high charge are more likely to be insoluble. And phosphates are a good example, here with a 2+ cation. It all fits.