Problem: A solution of formic acid (HCOOH, Ka = 1.8 X 10 -4) has a pH of 2.70. Calculate the initial concentration of formic acid in this solution.

🤓 Based on our data, we think this question is relevant for Professor Dixon's class at UCF.

FREE Expert Solution

We’re being asked to calculate the initial concentration of formic acid, HCOOH solution with a pH = 2.70.


For this, we need to do the following steps:

Step 1: Write the dissociation reaction of HCOOH solution in water

Step 2: Construct an ICE chart to determine the initial concentration of HCOOH

Step 3: Solve for H3O+ concentration at equilibrium from the given pH

Step 4: Calculate the initial concentration of HCOOH based on the given Ka


Step 1: Remember that weak acids partially dissociate in water and that acids donate H+ to the base (water in this case). 


The dissociation of HCOOH is as follows:

HCOOH(aq) + H2O(l)  H3O+(aq) + COOH(aq)

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Problem Details

A solution of formic acid (HCOOH, Ka = 1.8 X 10 -4) has a pH of 2.70. Calculate the initial concentration of formic acid in this solution.

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 Acids concept. If you need more Weak Acids practice, you can also practice Weak Acids practice problems.

What professor is this problem relevant for?

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

What textbook is this problem found in?

Our data indicates that this problem or a close variation was asked in Chemistry: An Atoms First Approach - Zumdahl 2nd Edition. You can also practice Chemistry: An Atoms First Approach - Zumdahl 2nd Edition practice problems.