1. Oct 21, 2006

### jhs1st

i'm having a hard time with writing net inoic equations and here are some sample problems with the answers I came up with.

Please look over them and if somethings wrong, please correct the errors teach me how to fix it.

1. A strip of copper is immersed in dilute nitric acid

Cu + HNO3 -> Cu(NO3)2

2. Excess concentrated ammonia solution is added to a suspension of silver chloride.

Ag+ + OH- -> AgOH

3. Solution of tri-potassium phosphate and zinc nitrate are mixed

3Zn+ + (PO4)^-3 -> Zn3PO4

4. Concentrated hydrochloric acid is added to solid manganese (II) sulfide.
Mn^+2 + Cl2- -> MnCl2

and the rest of them below, I had no clue on how to even start

1. Potassium permanganate solution is added to an acidic solution of hydrogen peroxide

I got KMnO4 + H2O2 -> KMnO4 + H + O2^-2
but i hit the wall right here...
I'm guessing that the product is HMnO4 but i'm not confident at all.

2. Excess chlorine gas is passed over hot iron filings

Cl2 + Fe^2+ ???????? sorry..but i couldnt figure this one out either

3. Water is added to a sample of solid magnesium nitride

4. Excess sulfur dioxide gas is bubbled thru a dilute solution of potassium hydroxide

p.s. thank you so much for reading this. But if you have an extra time, would you give some tips on writing an ionic equations? or list some most common mistakes that students make when they first learn this?

2. Oct 21, 2006

### Stevedye56

Im assuming this are for precipitate reactions and not redox... if this is the case this might help. http://www.ausetute.com.au/ppteeqtn.html
Break everything down to ions except the solid precipitate on the resultant side, then you know what your spectators are. Hope this helps

Steve

3. Oct 29, 2006

### mineys

no....looks like there are some redox reactions in there too. Those last couple are definatly redox.
for #4, where did you get the Cl2-? Concentrated hydrochloric acid solution is H+ + Cl-.
I think that "Most chloride, bromide, and iodide salts are soluble with the notable exeptions of salts containing the ions Ag+ Pb2+ and Hg2+.
for the potassium permanganate one, a good rule to follow is that potassium permanganate is almost always a catalyst, and does not change, but your hydrogen peroxide will speed its way into decomposition into water and oxygen gas.
On the first #1, there is a specific rule for thes reaction which is "Copper reacts with DILUTE nitric acid to produce copper(II) nitrate, nitrogen monoxide, and water.
I'm not sure about the chlorine and iron one or the water and magnesium nitride one.
I can find no error in the rest of them, and please don't take it hard that some of your answers are not correct. It took me about a year to learn how to predict reactions to the ability that i can now, and obviously I still can't do them all. They are really tough.

4. Oct 29, 2006

### Stevedye56

When i posted i dont even think those were there. I know there is no edit but i never saw those. But you are right those are definately redox.