# Homework Help: Help writing a few basic formulae

1. Aug 15, 2006

### Muzzae

I'm assuming this is the correct forum, please tell me if it isn't so I'll know if future.

I'm new to the whole formulae thing, and need some help with some (presumably) easy formulae. How would I write the following in both words and symbols? I've done as much work as I know how to do, so sorry if I come across as being naive.

-Sodium Hydroxide + Sulfuric Acid =...

-Calcium Hydroxide + Hydrochloric Acid=...(Calcium Chloride + Water)

-Magnesium Hydroxide + Nitric Acid=...(Magnesium Nitrate + Water)

Last edited: Aug 15, 2006
2. Aug 15, 2006

### Cesium

Well since this is a homework problem, you should actually have posted here. https://www.physicsforums.com/forumdisplay.php?f=157

All of those reactions are that between a base and an acid. Hydroxides (OH-) are common bases. Ammonia (NH3) is a common weak base.

the hydroxide ion is OH-
the sodium ion is Na+

NaOH sodium hydroxide
sulfuric acid is H2SO4

2NaOH + H2SO4 --> Na2SO4 + 2H2O

Your book should tell you how to write the forumla for all of these compounds. As for the reactions look up acid-base neutralization; you always get a salt and water. But you really need to show more effort before I can help you out more :-/

3. Aug 15, 2006

### Muzzae

My book hardly tells me anything and I have an awful teacher; all I need are these three answers to work off; sorry if I sound kind of demanding, but I honestly don't want mean to sound like I am.

4. Aug 15, 2006

### Cesium

Can you come up with the formula for calcium and magnesium hydroxide? What are the charges on the calcium and magnesium ions? (and your edit for the products are correct)

Last edited: Aug 15, 2006
5. Aug 15, 2006

### Muzzae

Formula for calcium hydroxide=CaOH; magnesium hydroxide=MgOH. Regarding the charges on the ions, I haven't learned that too well as of yet, however I have learned valencies. Calcium's valency is 2(+); magnesium's valency is 2(+).

Furthermore, hydrochloric acid=HCl; nitric acid=HNO3.

Last edited: Aug 15, 2006
6. Aug 15, 2006

### Cesium

Good. Hydrochloric acid has a H+ and a Cl- ion. That is, a hydrogen ion and a chloride ion.
Nitric acid has a hydrogen ion and a nitrate ion (NO3-). When the acid ends in -ic, use an -ate ion.

Wrong! Hydroxide has a negative one (-1) charge. Ca as you said has a +2 charge. So you must have two hydroxide ions per Ca+2. Same goes for magnesium! Make sure you group polyatomic (more than one atom) ions (hydroxide and nitrate are for example polyatomic ions) using paranthesis.

http://www.ausetute.com.au/namiform.html

Last edited: Aug 15, 2006
7. Aug 15, 2006

### Muzzae

Damn, in my classes we've just been using valencies..=/ (P.S. thanks for the links)

Edit: Uh, have I shown sufficient effort?

Last edited: Aug 15, 2006
8. Aug 15, 2006

### Muzzae

*bump* Please, this is the only question I'll ever need to ask here and I need the answer ASAP - I've done all I can with them, please, someone show me the answers!

9. Aug 15, 2006

### Gokul43201

Staff Emeritus
Sorry Muzzae, we CAN NOT do that.

You must first understand the basics of valency and compound formation from different chemical species.

http://www.syvum.com/cgi/online/serve.cgi/squizzes/chem/compds3.html
http://www.bookrags.com/sciences/chemistry/formula-chemical-woc.html
http://www.southwest.com.au/~jfuller/chemistry/chem5.htm

You have to learn the basics correctly. You can't expect to skip past them and get answers to higher level questions.

http://misterguch.brinkster.net/6typesofchemicalrxn.html

There are no short cuts here.

Last edited: Aug 15, 2006
10. Aug 16, 2006

### Muzzae

Oh well, thanks anyway. I didn't know it was a "higher level" question, seeing as my teacher gave it as homework (I'm in grade 9, by the way). Again, thanks anyway. I think this thread has served it's purpose since I got the answers.