Problem: Calculate the pH of a 0.10 M solution of sodium formate (NaHCOO) given that the Ka of formic acid (HCOOH) is 1.8 x 10-4.

FREE Expert Solution

We are being asked to calculate the pH for a 0.10 M solution of C6H5NH2. 


NaHCOO is the salt form of the conjugate base of HCOOH.


NaHCOO disociates as: 

NaHCOO(aq) → Na+(aq) + HCOO-(aq)


The acid dissociation goes as: 

HCOOH(aq) + H2O(l) → HCOO-(aq) + H3O+(aq)



Since we’re dealing with a weak base and Kb is an equilibrium expression we will have to create an ICE chart to determine the equilibrium concentration of each species:

HCOO-(aq) weak baseproton acceptor
H2O → will act as the weak acidproton donor


Equilibrium reaction:        HCOO-(aq)  + H2O(l)  HCOOH(aq) + OH-(aq)


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Problem Details

Calculate the pH of a 0.10 M solution of sodium formate (NaHCOO) given that the Ka of formic acid (HCOOH) is 1.8 x 10-4.

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Weak Bases concept. If you need more Weak Bases practice, you can also practice Weak Bases practice problems.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Guloy's class at UH.