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 --> ?