So I am having trouble with my chemistry.

What I don't understand is what to do when you are predicting the products of a chemical equation, and knowing what its physical state is

for example

Hg (NO3)2 + Na2S -->

I looked at my activity series and Sodium is more reactive than Mercury so I got

Na(NO3) + HgS

then balanced the equation would look like

Hg(NO3)2 + Na2S --> 2Na(NO3) + HgS


so is that right?

am I going in the right direction?

but how do you find out its physical state?

any help would be wonderful!

here is another

H2S04 + Ca(NO3)2 --> ?

Hg(NO3)2 + 2NaS --> 2Na(NO3) + Hg2S

should be the correct balanced equation, though I did a fast job so it might be wrong. Hg is a transition metal so I'm a bit uncertain of the common valence.

But you are on the right track, predicting a chemical reaction is easy, most usually consist of acid base.

Thanks!

There are general physical properties of many chemicals (http://www.intute.ac.uk/sciences/reference/plambeck/chem2/p01183.htm) which allow an educated guess, but often it is easiest to go to a reference source to find out the physical property of products in a reaction.

In this case soluble (aq = aqueous solution) reactants form insoluble (s = solid) products:

Hg(NO3)2 (aq) + Na2S (aq)-->2Na(NO3) (aq) + HgS (s)

H2S04 (aq)+ Ca(NO3)2 (aq)--> CaSO4(s) + H2NO3(aq)

help me to do this work balance molecular equations?

___ Fe + ____ S --> ___ FeS