[nikestied]

We did a lab in chemistry class, where we mixed a bunch of nitrates (Zinc nitrate, calcium nitrate, ect.) with metals (zinc, calcium, ect.)  I have to do a lab report, and I have to include single replacement reactions for all of them, but I'm having trouble with the calcium ones.  I know that they have to give off hydrogen gas, because my teacher made a big point about it.  Where does that hydrogen gas come from? Is it just from the hydrogen in the water of the calcium nitrate?  And if it is, how do I illustrate that in the replacement reactions?  I know that you aren't supposed to show the water in an aqueous solution.

One other problem I'm having, is can a nitrate react with a metal like itself? (like calcium nitrate + calcium or iron nitrate + iron)  It doesn't look like they would, because the metal would have exactly the same reactivity as the ion in the nitrate, but when I conducted the experiment, Calcium reacted a lot with calcium nitrate and produced a white chalky substance, iron reacted with iron nitrate, and tin reacted with tin nitrate.  If they do react, how do you show this in the reaction?  Ca + Ca(NO₃)₂ --> Ca + Ca(NO₃)₂ ??  That doesn't make any sense at all!!!

Please help me if you can A.S.A.P!! I have to turn in my lab on
Monday!!

[Albert]

We did a lab in chemistry class, where we mixed a bunch of nitrates (Zinc nitrate, calcium nitrate, ect.) with metals (zinc, calcium, ect.)  I have to do a lab report, and I have to include single replacement reactions for all of them, but I'm having trouble with the calcium ones.  I know that they have to give off hydrogen gas, because my teacher made a big point about it.  Where does that hydrogen gas come from? Is it just from the hydrogen in the water of the calcium nitrate?  And if it is, how do I illustrate that in the replacement reactions?  I know that you aren't supposed to show the water in an aqueous solution.

Ca_(s)  +  2H₂0 ->  Ca(OH)₂  + H_2(g)

This reaction takes place with almost all the element belonging to the second group.

[nikestied]

Ca_(s)  +  2H₂0 ->  Ca(OH)₂  + H_2(g)

This reaction takes place with almost all the element belonging to the second group.

But thats not calcium nitrate, we were working with cacium nitrate, not calcium hydroxide.  Thats why I'm confused about where the hydrogen comes from.  There's no hydrogen in the calcium nitrate or any of the metals we added to it, so where does it come from? The water in the calcium nitrate solution?

Thanks for replying so fast, by the way!  

[Albert]

We did a lab in chemistry class, where we mixed a bunch of nitrates (Zinc nitrate, calcium nitrate, ect.) with metals (zinc, calcium, ect.)

I thought you had also solid metals in your test tube(s).

[nikestied]

I thought you had also solid metals in your test tube(s).

Yes, we put the nitrates in the test tubes then the metals.  So what you're saying is that the metal is actually reacting with the water in the solution to produce hydrogen gas and a base?  So when I'm writing out the reactions, what do I do with the calcium nitrate?  And if that where true, whouldn't all the metals then produce hydrogen gas and a base?  That can't be true, because one of the big points of the experiment was that calcium would produce hydrogen gas and the other metals wouldn't, making calcium highly dangerous.

[Albert]

Of course not all the metals react this way. As I wrote, this very kind of reaction takes place with elements of the first two groups (for what concerns the first one it's generally MORE violent).

For example, you mentioned Zn_(s), didn't you? Well, zinc produces H_2(g) only if there's also an acid: that's why it's less dangerous.

[nikestied]

Of course not all the metals react this way. As I wrote, this very kind of reaction takes place with elements of the first two groups (for what concerns the first one it's generally MORE violent).

For example, you mentioned Zn_(s), didn't you? Well, zinc produces H_2(g) only if there's also an acid: that's why it's less dangerous.

Oh I get it. So I would write the reaction:
Ca(NO₃)_2(Aq) + 2H₂O_(l) + Zn_(s) = Zn(NO₃)₂ + Ca(OH)₂ + H₂ ?

[Albert]

If I were you, I'd not try to write a chemical equation that contains all the reactions occuring in my test tube.
However, for what concerns zinc, check these reactions out:

3 Zn_(s) +  8HNO₃  ->  3 Zn(NO₃)₂ + 2NO_(g)  + 4H₂O

3Zn_(s) + 4Zn(NO₃)₂  -> 3Zn(NO₃)₂  + 2NO_(g) + 4ZnO

I performed the former many times. I worked out the latter and I don't see anything against it. I mean: it sounds possible.

[Borek]

(aq), (s) and (g) should be the same size rest of the formula is.

[Albert]

Sorry, man, but this is just an Italian 'tradition'.

[nikestied]

Thank you all for all your help. This truely is a great site.