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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: browneyedbella on October 07, 2008, 12:19:21 AM

Title: Net Ionic Equations
Post by: browneyedbella on October 07, 2008, 12:19:21 AM
So my professor gave out a sheet of net ionic equations to do. And needless to say I'm pretty lost. what I have typed under the number is as far as i get!!! PLEASE HELP. seriously, anything would be great.

Write balanced net ionic equations for any of the reactions that occur when aqueous solutions of the following compounds are mixed. If there is no reaction, give NR. Also - tell what type of reaction is occurring: precipitation, acid (base or oxidation-reduction)

1. chromium metal and hydroiodic acid.
I'm pretty sure this one has NR.

2. barium bromide and potassium chromate.

BaBr2 + K2CrO4

3. magnesium hydroxide and nitrous acid.
Mg(OH)2 + HNO2

4. cobalt sulfate and lithium sulfide.
CoSO42- + Li2S

5. mercury (II) nitrate and ammonium iodide.
Hg(NO3)2 + NH4I

6. silver acetate and aluminum sulfate.
AgC2H3O2 + Al2(SO4)3

7. nickel (II) bromide and potassium phosphate.
__________ + KH2PO4

8. calcium carbonate and nitric acid
CaCO3 + HNO3

9. sodium hydroxide and copper (II) sulfate
NaOH + Cu(SO)4

10. calcium chloride and cadmium metal
CaCl2 + _______

11. ammonia and perbromic acid.
NH3 + HBrO4

12. mercury metal and lead nitrate.
Hg + Pb(NO3)2

13. zinc sulfite and sulfuric acid.
______ + H2SO4

14. magnesium metal and tin (IV) chloride.
Mg2+ + SnCl4
Title: Re: Net Ionic Equations
Post by: AWK on October 07, 2008, 01:03:54 AM
Read forum rules and show your attempt.

Ammonia and metallic cadmium are neutral species not ionic.
Note - perbromic acid is extremely unstable and will decompose into water, bromine and oxygen before reaction with a weak base.
Title: Re: Net Ionic Equations
Post by: nj_bartel on October 07, 2008, 01:18:19 AM
Quote
Note - perbromic acid is extremely unstable and will decompose into water, bromine and oxygen before reaction with a weak base.

I don't think he needs to know that, does he?  Just going to complicate it.
Title: Re: Net Ionic Equations
Post by: browneyedbella on October 07, 2008, 01:27:16 AM
Hello. I don't mean to be rude here, but the above was my attempt. My professor only gave us the names of each solution. Maybe it'd be helpful if I knew what the solubility rules did? Maybe then I could post an attempt to answering them?

Again, this isn't meant to be rude. I just really don't understand this. Sorry.
Title: Re: Net Ionic Equations
Post by: nj_bartel on October 07, 2008, 01:36:20 AM
--------------------------------------------------------------------------------
 http://en.wikipedia.org/wiki/Precipitation_(chemistry)
 http://en.wikipedia.org/wiki/Single_displacement_reaction
 http://en.wikipedia.org/wiki/Metathesis_reaction_(chemistry)
 http://www.csudh.edu/oliver/chemdata/solrules.htm
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
 http://en.wikipedia.org/wiki/Neutralization_(chemistry)
 http://en.wikipedia.org/wiki/Acid
 http://en.wikipedia.org/wiki/Base_(chemistry)
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
 http://en.wikipedia.org/wiki/Redox
--------------------------------------------------------------------------------

Read those pages and try to understand the gist of them.  If there's something you don't understand in one of them, ask a specific question about it.
Title: Re: Net Ionic Equations
Post by: browneyedbella on October 07, 2008, 01:49:45 AM
just to see if I'm getting the hang of things...

cobalt sulfate and lithium sulfide

Co8++SO42- + Li++S2-
CoSO42- + Li2S  :rarrow: Li2S




barium bromide and potassium chromate
Ba2+Br + K+Cr6+O42-
BaBr2 + K2CrO4  :rarrow: BaK + CrO4



magnesium hydroxide and nitrous acid
3 Mg(OH)2 + 2 HNO3  :rarrow: MgH + OH2


??
Title: Re: Net Ionic Equations
Post by: browneyedbella on October 07, 2008, 02:24:05 AM
please see original post for my answers.

corrections would be great.

also. i included the kind of reaction at the bottom. if its wrong, please correct and/or tell me why?

thanks so much!
Title: Re: Net Ionic Equations
Post by: browneyedbella on October 07, 2008, 02:37:11 AM
So my professor gave out a sheet of net ionic equations to do. And needless to say I'm pretty lost. what I have typed under the number is as far as i get!!! PLEASE HELP. seriously, anything would be great.

Write balanced net ionic equations for any of the reactions that occur when aqueous solutions of the following compounds are mixed. If there is no reaction, give NR. Also - tell what type of reaction is occurring: precipitation, acid (base or oxidation-reduction)

1. chromium metal and hydroiodic acid.
I'm pretty sure this one has NR.

2. barium bromide and potassium chromate.
BaBr2 + K2CrO4 :rarrow: BaK + CrO4

3. magnesium hydroxide and nitrous acid.
Mg(OH)2 + HNO2  :rarrow: MgH + OH2
precipitation

4. cobalt sulfate and lithium sulfide.
CoSO42- + Li2S  :rarrow: Li2S

5. mercury (II) nitrate and ammonium iodide.
Hg(NO3)2 + NH4I  :rarrow: Hg2I

6. silver acetate and aluminum sulfate.
AgC2H3O2 + Al2(SO4)3  :rarrow: AgAl2

7. nickel (II) bromide and potassium phosphate.
NiBr + KH2PO4  :rarrow: NiH2 + KPO4

8. calcium carbonate and nitric acid
CaCO3 + HNO3  :rarrow: CaCO3 + H

9. sodium hydroxide and copper (II) sulfate
NaOH + Cu(SO)4   :rarrow: NR

10. calcium chloride and cadmium metal
CaCl2 + Cd  :rarrow: CaCd
precipitation

11. ammonia and perbromic acid.
NH3 + HBrO4  :rarrow: NH4 + BrO4
oxidation reduction

12. mercury metal and lead nitrate.
Hg + Pb(NO3)2  :rarrow: HgPb2
precipitation

13. zinc sulfite and sulfuric acid.
ZnSO2 + H2SO4  :rarrow: H2O + ZnSO4
acid base reaction

14. magnesium metal and tin (IV) chloride.
Mg2+ + SnCl4  :rarrow: Mg4Cl2 + Sn



NOTE: I'm not sure if they are all balanced. And I'm not sure what state they are in (Aq, liq, gas). If you catch any mistake (which there are probably alot) please *delete me*

Again, I'm not good at this at all. Any help would be great!
Title: Re: Net Ionic Equations
Post by: Borek on October 07, 2008, 03:07:14 AM
Quote from: browneyedbella on October 07, 2008, 02:37:11 AM
1. chromium metal and hydroiodic acid.
I'm pretty sure this one has NR.

Metal in very strong acid.

Quote
2. barium bromide and potassium chromate.
BaBr2 + K2CrO4 :rarrow: BaK + CrO4

You are mixing two salts. Check solubility of barium chromate. Besides, you can't combine any ion with any ion - ionic salts have a cation and an anion, not two cations. And where is bromide on the right?

Quote
3. magnesium hydroxide and nitrous acid.
Mg(OH)2 + HNO2  :rarrow: MgH + OH2
precipitation

Again, you are combining wrong ions. You have a base and an acid.

Quote
4. cobalt sulfate and lithium sulfide.
CoSO42- + Li2S  :rarrow: Li2S

Half of your reactants disappeared. Check solubility rules.

You repeat similar mistakes now and again, so analyze these and redo the rest.
Title: Re: Net Ionic Equations
Post by: AWK on October 07, 2008, 04:30:25 AM
Quote from: browneyedbella on October 07, 2008, 01:49:45 AM
just to see if I'm getting the hang of things...

cobalt sulfate and lithium sulfide

Co8++SO42- + Li++S2-
CoSO42- + Li2S  :rarrow: Li2S




barium bromide and potassium chromate
Ba2+Br + K+Cr6+O42-
BaBr2 + K2CrO4  :rarrow: BaK + CrO4



magnesium hydroxide and nitrous acid
3 Mg(OH)2 + 2 HNO3  :rarrow: MgH + OH2


??
write down like this
Co2+(aq) + S2-(aq) = CoS(s)