Question

Which has a higher `pH` value : `0.01 M` `NaOH` or `0.1 M` `NaHCO_3`?

Answer 1

`0.01M \ NaOH`

Explanation:

To calculate the `pH` of `0.01M \ NaOH`, let's calculate the `pOH` first, because `NaOH` dissociates into `Na^+` and `OH^-` when dissolved in water.

`pOH=-log[OH^-]`

`pOH=-log[0.01]=2`

Know that here,

`pOH+pH=14`, (Source: https://socratic.org/questions/why-does-ph-poh-14)

`pH=14-2=12`

So, a `0.01M \ NaOH` solution will have a `pH` of `12`.

I'm not sure about how to calculate the `pH` of `NaHCO_3`, but I found online, that `0.1M \ NaHCO_3` at `25^@C` has a `pH=8.3`.
(Source: https://pubchem.ncbi.nlm.nih.gov/compound/sodium_bicarbonate)

So, `0.01M \ NaOH` has a higher `pH` than `0.1M \ NaHCO_3`.