The formula to calculate pK_{a} from the K_{a} value is –

∴ pK_{a} = -log_{10}(K_{a})

Ka to pKa calculator

K_{a} to pK_{a} Calculator

pK_{a} =

Step by Step Solution:

To determine pK_{a}, you can use this formula given below:

⇒ pK_{a} = -log(K_{a})

Given that,

⇒ K_{a} =

Substitute the [K_{a}] value into the formula:

∴ pK_{a} = -log()

∴ pK_{a} =

How to use K_{a} to pK_{a} calculator?

Using the above calculator you can easily convert the K_{a} value to pK_{a}.

Enter a K_{a} value in the input field labeled “K_{a} value =”.

Click the “Calculate” button.

The result [pK_{a}] will be displayed in the “result” section with Step by Step solution.

Note:Most of the time the K_{a} value given in the problem is represented in scientific notation, for example, 5.49 × 10^{-8}, 2.33 × 10^{-11}, etc.

These values can also be written as –

⇒ 5.49 × 10^{-8} = 5.49e-8

⇒ 2.33 × 10^{-11} = 2.33e-11

So, in the “K_{a} to pK_{a} calculator” put the value of K_{a} which is given in scientific notation as described above like [5.49e-8, 2.33e-11].

How to calculate pK_{a} from K_{a}?

pK_{a} is the negative logarithm of K_{a} to the base 10 as shown in the formula given below:

∴ pK_{a} = -log_{10}(K_{a})

Example of calculating pK_{a} value using “K_{a} to pK_{a} calculator”

Let’s say we have given the value of K_{a} and we need to calculate the pK_{a} value.

For example – If the K_{a} value = 1.34 x 10^{-5}, what is the [pK_{a}] value?

As we know, the formula to convert K_{a} to pK_{a} is –

∴ pK_{a} = -log_{10}(K_{a})

Note:- As the given K_{a} value in scientific notation which is 1.34 x 10^{-5}, this value can also be written as “1.34e-5”.

So, Just put this value of [K_{a}] in the calculator field, and press calculates button to get step by step solution.

∴ So, the approx pK_{a} value for given K_{a} is 4.87.

Numericals based on “Converting pK_{a} value to K_{a}“

The K_{a} value for a weak acid is given to be 2.33 x 10^{-11}. What can be the pK_{a} value for its acidic solution?

To find the value of the pK_{a} for the acidic solution, we can use the equation given below –

⇒ pK_{a} = -log_{10}(K_{a})

We have given, the K_{a} value which is 2.33 x 10^{-11}, it can also be written as 2.33e-11.

∴ [pK_{a}] = -log_{10}(2.33 x 10^{-11}) [∴ Put the value of K_{a} in “K_{a} to pK_{a} calculator” as 2.33e-11]

= 10.63

So, the pK_{a} for the given K_{a} value is 10.63.

The K_{a} for acetic acid is 1.58 x 10^{-5}. What is the pK_{a} value for acetic acid?

As the K_{a} value for acetic acid is given in the question statement. So we can substitute it into the equation given below to find pK_{a} as follows.

⇒ pK_{a} = -log_{10}(K_{a})

∴ pK_{a} = -log_{10}(1.58 x 10^{-5}) [∴ Put the value of K_{a} in “K_{a} to pK_{a} converter” as 1.58e-5]

= 4.80

So, the pK_{a} value for the given K_{a} of acetic acid is 4.80.

Vishal Goyal is the founder of Topblogtenz, a comprehensive resource for students seeking guidance and support in their chemistry studies. He holds a degree in B.Tech (Chemical Engineering) and has four years of experience as a chemistry tutor. The team at Topblogtenz includes experts like experienced researchers, professors, and educators, with the goal of making complex subjects like chemistry accessible and understandable for all. A passion for sharing knowledge and a love for chemistry and science drives the team behind the website. Let's connect through LinkedIn: https://www.linkedin.com/in/vishal-goyal-2926a122b/

Topblogtenz is a website dedicated to providing informative and engaging content related to the field of chemistry and science. We aim to make complex subjects, like chemistry, approachable and enjoyable for everyone.