Question

Complete and Balance each gas-evolution equation.

Answer 1

\[HBr(aq)+Ni(s) \rightarrow\]

Answer 2

My attempt was that
\[H _{2}S (g) + NiB(aq)\]

Answer 3

Not sure if thats right.

Answer 4

Apparently sulfides don't have an intermediate product so it turns into a "gas".

Answer 5

Well you have to know different kinds of reactions and balancing rules.

Answer 6

Now we are involved with single replacement and double replacement reactions.

https://www.youtube.com/watch?v=qhmTXdOKTBo
Single replacement reaction is a reaction in which one element replaces another element in a compound !

Double replacement reaction is a reaction when two elements in different compounds replace each other!

After learning these two replacement reactions we get to reactivity series which usually is included in some periodic tables. If not in yours then check this out!
http://www.edplace.com/userfiles/image/Reactivity%20Series%20ADDED.jpg

More reactive replaces less reactive. However, less reactive cannot replace higher reactive elements. You only have to know these series for single replacement reaction not double rep reaction. Ask your teacher and I am sure he will give it to you.

Now balancing needs practicing a lot.
http://misterguch.brinkster.net/eqn1.jpg
This is a good way for beginning.

Answer 7

I also give examples for each to you!