Question for you guys...

I'm tutoring a Grade 9 student in math and she asked if I could help her go over some chemistry. I took chemistry right through grade 12 but that was 8 years ago and haven't looked at the stuff since. I know she needs help with lewis dot diagrams and I'm reteaching myself the material. It's all straight forward and I'm comfortable with it, but then I came across ammonium chloride.

So, in my understanding, an ionic bond needs to have a metal to form. But NH4Cl is ionic, despite being formed of three non-metals. Why?

Also, what would the lewis dot structure look like? Google is showing me about 5 different images and none are really well explained.

Finally, but probably most importantly, is this something that would be taught at the Grade 9 level or is this more advanced stuff that my student doesn't need to know yet?

From the worksheets that she's shown me the type of stuff they're doing in class is like... CH3BR, NO2-1, SO4-2, NACl, NBr, that type of basic and straight-forward stuff.

dont you hate it when you start a serious thread and no one responds, and then you see, what is this? a response? YESSSS lets check it out, and then you see that the response is nothing but an insane run-on sentence that really answers nothing that you asked?

i hate that fluff too.

Then comes the follow up reply making fun of the first response.

i'll just leave this here

http://www.youtube.com/watch?v=gZEdDMQZaCU

Just my thoughts i´m no expert in this

So, in my understanding, an ionic bond needs to have a metal to form. But NH4Cl is ionic, despite being formed of three non-metals. Why?

NH4 is a combination of N and 4 H. H has one electron and would need one to become stable. It gets those electrons from N that has 5 available. So the 4 H get 1 electron each from N. Then N has one extra electron left which makes it NH4+. Then comes along Cl- and takes the last one away from the N making it NH4Cl?

Metals usually have extra electrons and wants to give them away. Hence some metals rust cus they bond with oxygen. Neon a nobel gas would however not bond cus it has 8 electrons on the second ring so its full and that element is stable.

Someone my come along and declare this bullfluff so dont trust this at all :D Havent studied chemistry since high school and this information should be read with that in mind!

The answer is .999999999999999 = 1

1. You don't need a metal to form an ion. Look at NO3 -, PO4 3-, CO3 2- for example. I can't tell u WHY, it is so.

2. Now with N you picked one slippery dude, cause it can have all kinds of different oxidation states, including 3- in ur case. So three 4 H's bond to N making it NH4 + and along comes Cl- and sticks to it.

3. Lewis structure should look like this: one solo dot above N, plus 4 dashes connecting it to the 4 H's. then u draw a big bracket around that monster with an upper "+" and then put ur Cl- next to it.

4. Cl- will have 4 dashes (i.e. 8 dots) around it representing the electrons.

5. I think that does it, if not, we're at least getting pretty close to it.

paceboom is pretty close but he missed a couple key things!

as far as i know, ionic bonds are not real bonds. they're just interactions of two ionic species that is not considered to be truly covalent. covalent bond is when the ionic species share electrons with each other. hence, an ionic bond is simply when the electrons are not shared within their electron cloud orbital, BUT due to their respective charges there is an attraction between the two species. if you really want to get the nitty gritty of what a "bond" is, its all about the energy required to pull the two species apart. its all about thermodynamics!


i would say that what i have written above should be 'hand-wavable' information. a 9th grader could easily just memorize it, but should they be expected to have true conceptual knowledge of how and why it works the way i say it does? i'd say likely not.


as far as lewis dot structures go - they're not real :P

but the ammonium (NH4) shuold not have an electron shown on it. instead, it just has the nitrogen with 4 hydrogens attached to it with a + sign next to the N. this is because nitrogen naturally has 5 electrons but is receiving electrons 6-9 from hydrogen (they're sharing them so this is a perfect example of covalent bond). that 9th hydrogen is what imparts the + charge.

Cl- is a natural ion due to the stability that a 7 electron cloud naturally has. they're just one away from noble.

An ionic bond does not need a metal to form, just a positive and a negative ion.

Based on my study of physical chemistry in uni, an "ionic" bond is a real bond in the sense that the compound still exists out of solution. (Like table salt for example) but of course the real answer is more complex than that. You cannot convince me that reacting NaCL with something does not cause a "bond" to break:P

Hydrogen can act as a metal or a non metal depending on the situation.

High school chemistry (even introductory university chemistry) is a gross simplification of reality but is a basis for better understanding later.