Urgent Chem Help got test in 2 days (1 Viewer)

[manutd12]

Ok so heres my problem, Im doing Chemistry prep in year 10 , and It has Totally done my head in. My teacher is the type of one which explains 10 topics in one lesson, so quickly and she tells us to ask questions and when we do , she like goes of yelling at us saying "oh you should of listened when i explained" she just brings out random words like that we've never heard of before and she expects us to magically know what it means.

For god sakes were in year 10 & some are in year 9 and she's teaching us late year 11 chemistry. Like wtff.. Ok so heres my problem I got a prac test on thurs and a theory test on tues. And um i magically have to know how to do Ionic Equations, Molecular Formulas, find spectator ions, & balance chemical equations for a precipitation experiment were going to be conducting. And im afraid of asking her cause she'll never let me hear the end of it, she thinks were all amazing chemistry students who just pick up everything that comes out of her bullshit mouth.

So how the do you work out an Ionic equation for :
Cobalt Chloride & Sodium Carbonate
Barium Chloride & Copper Sulfur

I know how to do the first two steps but its just does my head in with the valencies and all that crap .. im stressing I want to get a good grade in my report so far Iv received a B+ for a chem assignment on Metals and their properties, so I want to complete the trend.
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[DInfinity]

Cobalt Chloride + Sodium Carbonate -> Cobalt Carbonate + Sodium Chloride

Full ionic equation:
Co(2+) + 2Cl(-) + 2Na(+) + CO3(2-) -> CoCO3 + 2Na(+) + 2Cl(-)

Net ionic:
Co(2+) + CO3(2-) -> CoCO3 (the spectator ions are left out)


Barium Chloride + Copper Sulfate (<- I assume you mean that instead of sulfate) -> Barium Sulfate + Copper Chloride

Full ionic equation:
Ba(2+) + 2Cl(-) + Cu(2+) + SO4(2-) -> BaSO4 + 2Cl(-) + Cu(2+)

Net ionic:
Ba(2+) + SO4(2-) -> BaSO4

Method:
1. Write out the word equation, including the products
2. Use the solubility rules to determine which is the precipitate and which is soluble
3. Change that to a symbol equation, and balance
4. Separate the reactants and products into ions so that they don't appear 'joined' in the symbol equation
5. Spot the spectator ions (those that don't do anything) and remove from the full ionic equation, and remove
6. You have written a net ionic equation

So basically, ions are those that are in solution (aq), and net ionic equations are equations that involve ions (atoms with a charge) that actually do something. Take the first example, CoCl and NaCO3: Sodium and chlorine ions do nothing, so they are left out of the net ionic equation, whereas cobalt and carbonate combine to for a precipitate (a solid).

Okay, onto molecular formula. This gives the total number of each atom in a molecule. This means that there is no molecular formula for ionic compounds, covalent lattice compounds, metals etc. Only those that exist as molecules. Note that it is not the empirical formula - they are not simplified.

For example, the molecular formula for a bucky ball could be C60.

Another example, demonstrating the difference between the empirical and molecular formula of any isomer of butene:

Empirical: CH2
Molecular: C4H8

Balancing equations:
Change the co-efficients of molecules so that the number of X element on either side of the arrow is the same. Don't change the subscript number, as that would be like writing a totally different equation.

Good luck for your chem prac and theory. If you have any questions, you can PM me (so long as it is within year 11 range).

o.o that was a big rant. I think I deserve some rep *hint*.

 

[manutd12]

Cobalt Chloride + Sodium Carbonate -> Cobalt Carbonate + Sodium Chloride

Full ionic equation:
Co(2+) + 2Cl(-) + 2Na(+) + CO3(2-) -> CoCO3 + 2Na(+) + 2Cl(-)

Net ionic:
Co(2+) + CO3(2-) -> CoCO3 (the spectator ions are left out)


Barium Chloride + Copper Sulfate (<- I assume you mean that instead of sulfate) -> Barium Sulfate + Copper Chloride

Full ionic equation:
Ba(2+) + 2Cl(-) + Cu(2+) + SO4(2-) -> BaSO4 + 2Cl(-) + Cu(2+)

Net ionic:
Ba(2+) + SO4(2-) -> BaSO4

Method:
1. Write out the word equation, including the products
2. Use the solubility rules to determine which is the precipitate and which is soluble
3. Change that to a symbol equation, and balance
4. Separate the reactants and products into ions so that they don't appear 'joined' in the symbol equation
5. Spot the spectator ions (those that don't do anything) and remove from the full ionic equation, and remove
6. You have written a net ionic equation

So basically, ions are those that are in solution (aq), and net ionic equations are equations that involve ions (atoms with a charge) that actually do something. Take the first example, CoCl and NaCO3: Sodium and chlorine ions do nothing, so they are left out of the net ionic equation, whereas cobalt and carbonate combine to for a precipitate (a solid).

Okay, onto molecular formula. This gives the total number of each atom in a molecule. This means that there is no molecular formula for ionic compounds, covalent lattice compounds, metals etc. Only those that exist as molecules. Note that it is not the empirical formula - they are not simplified.

For example, the molecular formula for a bucky ball could be C60.

Another example, demonstrating the difference between the empirical and molecular formula of any isomer of butene:

Empirical: CH2
Molecular: C4H8

Balancing equations:
Change the co-efficients of molecules so that the number of X element on either side of the arrow is the same. Don't change the subscript number, as that would be like writing a totally different equation.

Good luck for your chem prac and theory. If you have any questions, you can PM me (so long as it is within year 11 range).

o.o that was a big rant. I think I deserve some rep *hint*.

Omg thanks I actually understood that, Lmao when I rant at her tomorow, I shall mention you lol. A random taught me chem in a min and all you have done is deafen me..
thanx =]

 

[mR sinister]

Lol,
Are you really, in year 10?
im guessing you got your SC, just to let you know SC is wayy tooo easy.

probably the hardest question you will get chem based is finding valencies haha

 

[DInfinity]

Just wondering, what school do you go to? o.0 Even at SGH we practically bludged the rest of year 10 after the SC (which we also bludged).

 

[manutd12]

I got BHGHS .. nahh well in the next two weeks i got 13 exams and two assignments due.. crazy eh.. The Sc trials was bull, because like I studied like 32 pages of science notes and not one piece of material was in that friggen exam it felt more like a comprehension test.

 

[manutd12]

I think I totally aced the chem.. thanx so much !! =]

 

[nosh22]

Relax.. you're in year 10.