Which has a higher pHpH value : 0.01 M0.01M NaOHNaOH or 0.1 M0.1M NaHCO_3NaHCO3?

1 Answer
Jan 16, 2018

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.