Please!!! I need Chemistry help!?

Question

I'm in this academic Chemistry class and it's way over my head. I have a test soon and i don't understand what we are doing in class at ALL!! The sad part is i don't even know what it's called that we are doing. I just stare at the problems he works out on the board and it just doesn't make sense to me. Its not like i don't try it's just so hard. Please either help me, or tell me a good website that could teach me. Here's an example of what we do in class:

Write the balanced formula, complete ionic, and net ionic equations for the reactions that occur when the following are mixed.
1. Solid silver hydroxide and hydrobromic acid
2. aqueous strontium hydroxide and hydroiodic acid

Another question i have is how do u tell if it is aqueous, solid or liquid? Please help me any help at all is appreciated Thanks

Answer 1

There are lots of things you can do to get help in class. I know the feeling of being completely lost - the important thing is to get it together before the test, so look for someone smart and with some time on their hands who also takes the class who can explain it to you. If that's not possible, ask the professor/teacher or the TA if there is one. Also, if there's a textbook, READ THROUGH IT! Start from the very beginning and if you get confused about something ASK someone. It really really helps, I promise.

As for your questions, they're quite easy.
1. Solid silver hydroxide is written as AgOH(s). If you didn't know that, you're much further back than you should be, and you need to go back to the beginning and look at the unit on nomenclature. Hydrobromic acid is HBr(aq). It's aqueous because all acids are aqueous. It's kind of hard to figure out what will happen when two things are mixed, but usually if you have a strong acid and a strong base, they form water and one other thing. That's called an acid-base equation. It's obvious that you have an acid, but where's the base? Well, whenever you see the word HYDROXIDE, think base. OH- is pretty much the strongest base around.
So... what's your equation?
AgOH(s) + HBr(aq) --> H2O(l) + AgBr
How did I get that? Well, just imagine that each compound breaks up. If AgOH breaks up, you get Ag+ and OH-. If HBr breaks up, you get H+ and Br-. Well, whenever you have OH- and H+ together in the same container, they will combine to form water, H2O. So you know H2O is one of the things that's formed. Well, what else is lying around? Ag+ and Br-, from each compound. Combine those and you get AgBr. Easy as pie.

2. Aqueous strontium hydroxide is Sr(OH)2(aq) and hydroiodic acid is HI(aq). Again, if you don't know why, go back to nomenclature. Notice that you've got a hydroxide and a base again - ACID/BASE REACTION! So you know water will be formed!
Sr(OH)2(aq) + HI(aq) --> H2O(l) + SrI2
Well, now you need to balance it, so put a 2 in front of the H2O and a 2 in front of the HI and you've got it balanced.

Hope I helped! I know even this can be confusing if you don't have a grasp of earlier material, so I really urge you to read the textbook if there is one. It will help. I promise.

Answer 2

As to what's aqueous, solid or liquid, unless otherwise specified, most equations that occur with acids are in liquid form. So in your reacions, everything that starts out is in water except the solid AgOH. You may also see the notation "(s)" next to a chemical to indicate it is solid.

When you have hydroxide-acid reagents, most of the time you are going to wind up with a salt and water. That is how they neutralize each other.

So in the first reaction, the products look to be AgBr and H2O. Some silver salts are not very soluble, so you might want to check to see if the AgBr will precipitate out as a solid. In this case, the formula is balanced as
AgOH + HBr -> AgBr + H2O

In the second reaction,
Sr (OH)2 + 2 HI -> Sr I2 + 2H2O

Answer 3

You need to start back at the chapter that teaches how to write an ionic formula.
Then how to write covalent formulas.
Then acids.
Then a whole chemical reaction.
Then learn about solutions. That's the chapter you're probably in. The problems are called NET IONIC EQUATIONS. But you have to know everything you have learned (or have not learned) previously.
You may need a real tutor. I'd spend some time with your teacher.

Answer 4

compounds dissolved in water are aqueous.However,you tutor will provide you with a solubility table.All soluble compounds are aqueous,insoluble ones are solids.Some chemistry books have the solubility table.There are weak acids which are not broken up in solution.Only strong acids separate in solutions. HClO4,HI,HBr,HCl,HNO3,H2SO4 and HCIO3 are the only strong acids whcih break up in solutions.you will only break up the compounds into ions if and only if they are "aqueous".Water is always a liquid unless specify by your tutor.An element in it's pure state is solid.so if you have Cu,it is solid.
1. Ag(OH)(s) + HBr(aq)------> AgBr(s) + H2O(l)
Ag(OH)(s) + H+(aq) + Br-(aq)---->AgBr(s) +H2O(l) =total ionic equation.*don't separate solids,liquids and gases.
2.Sr(OH)2(aq) + 2HI(aq)--------->SrI2(aq) +2H2O(l) formula unit
Sr+2(aq)+2OH-(aq)+2H+(aq)+2I-(aq)----> Sr+2(aq) +2I-(aq) +2H2O(l) total ionic equation
* now elminate the common ones:those on the product side and reactant side.
2OH-(aq)+2H+(aq)---->2H2O(l) net ionic equation

Ask your tutor for help.He/she will be more willing to help you understand.

Answer 5

I'm sorry that this all I can offer, but I use this great Chemistry website written by a Chemistry teacher/tutor.
http://www.chemfiesta.com/ or http://misterguch.brinkster.net/chemfiestanew.html
You can follow the link to the "Helpdesk" and then use the "Practice Worksheets" or "Mr. Guch Explains" or "Tutorial Links"