What kind of reaction is this (redox, precipitation, acid-base, or complex ion formation reaction)?

Question

1. 3 Ca(s) + 2 Al^3+(aq) -> 3 Ca^2+(aq) + 2 Al(s)

2. LiHCO3(s) + heat -> Li2CO3(s) + CO2(g) + H2O(g)

Complete the reaction: Ni(s) + 2 Na^+(aq) -> ?

Answer 1

First you must recognize that you can't crumple these things up and place them in a one box fits all. Some reactions may be more than one type.
2Na + 2H2O ==> H2 + 2NaOH
This is a redox rxn, a single replacement, and by some schemes even an acid/base rxn.

1. redox
2. decomposition
3. no reaction.

Answer 2

Thanks, but for the first one, I thought it'd be no reaction since they are both metals. Is it possible for Ca and Al to react with each other?

Answer 3

No but it isn't Ca and Al. Note it is Ca and Al^3+ ION