[soupastupid]

im thinking

RbOH is neutral

because Rb is a alkali metal
and the charges cancel out

and so NaHCO3 has to be the sole pH contributor
the ka for HCO3 is

5.6*10^-11 (does this number seem too low)

Na is neutral
HCO3 is a weak base

but when i do
HCO3- + H2O <--> H2CO3 + OH-
i get pOH = 5.56
pH = 8.43

does that look right?

[Borek]

RbOH is neutral

because Rb is a alkali metal

Because Rb is alkali metal, RbOH is a strong base, just like NaOH.

[soupastupid]

all alkali metals are strong bases when bonded with OH-?

so im think now...

RbOH is a strong base
and so
it completely dissociates into
RbOH --> Rb+ + OH-
and so i get
pOH = -log([RbOH])
pOH = 1.15
pH = 12.84

and i ignore NaHCO3 because it is a weak base?

[Borek]

all alkali metals are strong bases when bonded with OH-?

Yes.

and i ignore NaHCO3 because it is a weak base?

No. You don't ignore it. It is a weak acid as well. It will react with the strong base present in the solution. It is called neutralization reaction.

This is another limiting reagent question.