How to Calculate a pH
Know what pH actually is., Define pH in an equation., Understand concentration.
Step-by-Step Guide
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Step 1: Know what pH actually is.
The pH is the concentration of hydrogen ions in a solution.
A solution with a high concentration of hydrogen ions is acidic.
A solution with a low amount of hydrogen ions is basic, or also known as alkaline.Hydrogen ions, also known as hydronium, are written shorthand as H+ or H3O+.
Know the pH scale.
The pH scale is from 1-13.
The lower the number, the more acidic the solution.
The higher the number, the more basic the solution.For example, orange juice would have a pH of 2 because it is quite acidic.
In contrast, bleach has a pH of 12 as it is quite basic.Numbers in the middle of the scale are often neutral, such as water, with a pH of
7.
One level of pH is a 10x difference.
For example, when comparing pH 7 to pH 6, pH 6 is ten times more acidic than pH
7.
Furthermore, pH 6 would be 100 times more acidic than pH
8. -
Step 2: Define pH in an equation.
The pH scale is calculated by a negative logarithm.
A negative logarithm is simply how many times a number must be divided.The pH equation can be seen as follows: pH =
-log.
The equation can sometimes be seen as pH =
-log.
Know that whether the equation has H3O+ or H+, they are the same.
It is not vital to have a firm understanding of what a negative log is to calculate pH.
Most calculators used at high school and post secondary level will have a log button. , Concentration is the number of particles of a compound in a solution.Concentration is commonly described in molarity.
That is, moles per unit of volume (m/v or M).
If you’re using a solution in a lab, the concentration will be written on the bottle.
When working on your chemistry homework, the concentration will usually be given to you. -
Step 3: Understand concentration.
Detailed Guide
The pH is the concentration of hydrogen ions in a solution.
A solution with a high concentration of hydrogen ions is acidic.
A solution with a low amount of hydrogen ions is basic, or also known as alkaline.Hydrogen ions, also known as hydronium, are written shorthand as H+ or H3O+.
Know the pH scale.
The pH scale is from 1-13.
The lower the number, the more acidic the solution.
The higher the number, the more basic the solution.For example, orange juice would have a pH of 2 because it is quite acidic.
In contrast, bleach has a pH of 12 as it is quite basic.Numbers in the middle of the scale are often neutral, such as water, with a pH of
7.
One level of pH is a 10x difference.
For example, when comparing pH 7 to pH 6, pH 6 is ten times more acidic than pH
7.
Furthermore, pH 6 would be 100 times more acidic than pH
8.
The pH scale is calculated by a negative logarithm.
A negative logarithm is simply how many times a number must be divided.The pH equation can be seen as follows: pH =
-log.
The equation can sometimes be seen as pH =
-log.
Know that whether the equation has H3O+ or H+, they are the same.
It is not vital to have a firm understanding of what a negative log is to calculate pH.
Most calculators used at high school and post secondary level will have a log button. , Concentration is the number of particles of a compound in a solution.Concentration is commonly described in molarity.
That is, moles per unit of volume (m/v or M).
If you’re using a solution in a lab, the concentration will be written on the bottle.
When working on your chemistry homework, the concentration will usually be given to you.
About the Author
Victoria Jenkins
Professional writer focused on creating easy-to-follow organization tutorials.
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