Acid Base Calculator - Mathematical Calculations & Solutions
How It Works
Select Type
Choose calculation method
Calculate
Get pH, pOH, and ion concentrations
Common Examples
Neutral Water
[H⁺] = 1×10⁻⁷ M
pH = 7.0
Strong Acid
[H⁺] = 1×10⁻³ M
pH = 3.0
Strong Base
[OH⁻] = 1×10⁻² M
pOH = 2.0, pH = 12.0
Acid-Base Calculation Table
| Input | Formula | Result | Solution Type |
|---|---|---|---|
| [H⁺] = 1×10⁻⁷ M | pH = -log[H⁺] | pH = 7.0 | Neutral |
| [H⁺] = 1×10⁻³ M | pH = -log[H⁺] | pH = 3.0 | Acidic |
| [OH⁻] = 1×10⁻² M | pOH = -log[OH⁻] | pOH = 2.0 | Basic |
| pH = 4.5 | [H⁺] = 10^(-pH) | [H⁺] = 3.16×10⁻⁵ M | Acidic |
*pH + pOH = 14 at 25°C for all aqueous solutions
Acid Base Calculator
What
Calculate pH and pOH values from ion concentrations using logarithmic formulas.
Why
Essential for chemistry analysis, acid-base equilibrium, and analytical chemistry.
Applications
Chemistry education, laboratory analysis, and environmental science.
Calculation Examples
| Input | Formula | Result | Use Case |
|---|---|---|---|
| [H⁺] = 1×10⁻⁷ M | pH = -log₁₀[H⁺] | pH = 7.0 | Pure water (neutral) |
| [H⁺] = 1×10⁻³ M | pH = -log₁₀[H⁺] | pH = 3.0 | Strong acid (HCl) |
| [OH⁻] = 1×10⁻² M | pOH = -log₁₀[OH⁻] | pOH = 2.0, pH = 12.0 | Strong base (NaOH) |
| pH = 4.5 | [H⁺] = 10^(-pH) | [H⁺] = 3.16×10⁻⁵ M | Weak acid solution |
| pOH = 3.2 | [OH⁻] = 10^(-pOH) | [OH⁻] = 6.31×10⁻⁴ M | Basic solution |
Frequently Asked Questions
What is pH and how is it calculated?
pH measures hydrogen ion concentration using the formula pH = -log₁₀[H⁺]. Values below 7 are acidic, above 7 are basic, and 7 is neutral.
What is the relationship between pH and pOH?
At 25°C, pH + pOH = 14. This relationship comes from the water equilibrium constant Kw = 1.0 × 10⁻¹⁴.
How do I enter very small concentrations?
Use scientific notation (e.g., 1e-7 for 1×10⁻⁷) or decimal form (0.0000001). The calculator handles both formats accurately.
What are typical pH values for common substances?
Lemon juice: pH ~2, Coffee: pH ~5, Pure water: pH 7, Baking soda: pH ~9, Household ammonia: pH ~11.
Why is the pH scale logarithmic?
The logarithmic scale compresses the wide range of H⁺ concentrations (10⁻¹⁴ to 10⁰ M) into a manageable 0-14 scale.
Can pH be negative or greater than 14?
Yes, in very concentrated solutions. Negative pH occurs with [H⁺] > 1 M, and pH > 14 occurs with [OH⁻] > 1 M.
How accurate are these calculations?
The calculator uses precise logarithmic functions and is accurate for most laboratory and educational applications within standard concentration ranges.
Reverse Conversion
unit to math-calculator →Popular Converters
Quick Reference
What are Acids and Bases?
Acids and bases are everywhere around us! Think of lemon juice (acid) or soap (base). They are special chemicals that can change the taste, color, and properties of other things.
Acids taste sour and can dissolve metals. Bases taste bitter and feel slippery. When we mix acids and bases together, they can cancel each other out!
Scientists use numbers called pH to measure how acidic or basic something is. The pH scale goes from 0 to 14.
Key Points:
- pH 0-6: Acidic (like lemon juice)
- pH 7: Neutral (like pure water)
- pH 8-14: Basic (like soap)
- Lower pH = more acidic, Higher pH = more basic
How Does pH Work?
pH stands for "potential of Hydrogen." It tells us how many hydrogen atoms are floating around in a liquid. More hydrogen atoms mean more acidic!
Acidic Solutions
Lots of hydrogen ions (H+). Examples: vinegar, orange juice, stomach acid.
Basic Solutions
Lots of hydroxide ions (OH-). Examples: baking soda, soap, bleach.
Our acid base calculator helps you find the exact pH number for any solution!
Real Life Examples of Acids and Bases
Lemon Juice
pH = 2.0 - Very acidic! That's why it tastes so sour.
Coffee
pH = 5.0 - Mildly acidic, which gives coffee its tangy taste.
Pure Water
pH = 7.0 - Perfectly neutral! Not acidic or basic.
Hand Soap
pH = 9.0 - Basic solution that feels slippery.
Baking Soda
pH = 9.5 - Basic enough to neutralize stomach acid!
Bleach
pH = 12.0 - Very basic and strong cleaner!
How to Use the Acid Base Calculator
Our acid base calculator is super easy to use. Just follow these simple steps:
Pick Type
Choose what you want to calculate: pH, pOH, or ion concentration.
Enter Value
Type in the number you know (like pH or concentration).
Get Results
The calculator shows you all the answers instantly!
Learn More
See if your solution is acidic, neutral, or basic!
Acid Base Formulas Made Simple
pH Formula
pH equals negative log of hydrogen ion concentration
This formula helps us find pH when we know how many hydrogen ions are in the solution.
pOH Formula
pOH equals negative log of hydroxide ion concentration
This formula helps us find pOH when we know how many hydroxide ions are in the solution.
Water Rule
pH and pOH always add up to 14 in water
This is a special rule that works for all water solutions at room temperature.
Example Calculation
If [H+] = 0.001 M, what is the pH?
pH = -log(0.001) = -log(10⁻³) = 3.0
This solution has pH 3.0, which means it's acidic!
Why are Acid Base Calculations Important?
Understanding acids and bases helps us in many ways every day:
Cooking & Food
Baking soda makes cakes fluffy. Vinegar preserves food. pH affects taste!
Health & Medicine
Our blood must stay at pH 7.4. Antacids neutralize stomach acid.
Swimming Pools
Pool water needs the right pH to be safe and clean for swimming.
Cleaning Products
Basic cleaners remove grease. Acidic cleaners remove mineral deposits.
Environment
Acid rain harms plants. Ocean pH affects sea life and coral reefs.
Industry
Making paper, soap, and metals all need the right pH levels.
Common Questions About Acids and Bases
What happens when you mix an acid and a base?
They neutralize each other! The acid and base cancel out to make water and salt. This is why antacids help with stomach acid.
Why is pH 7 called neutral?
At pH 7, there are equal amounts of hydrogen ions (H+) and hydroxide ions (OH-). They balance each other out perfectly, like pure water.
Can pH be higher than 14 or lower than 0?
Yes! Very strong acids can have negative pH, and very strong bases can have pH above 14. But most everyday things stay between 0-14.
How do I enter very small numbers in the calculator?
You can type 1e-7 for 0.0000001, or just use the decimal form. Both work the same way in our calculator.
Why do we use logarithms for pH?
Ion concentrations can be tiny numbers like 0.0000001. Logarithms turn these into simple numbers like 7, making pH easy to work with.
Tips for Students
📚 Study Tips
- • Remember: Lower pH = more acidic
- • pH + pOH always equals 14
- • Practice with everyday examples
- • Draw the pH scale from 0 to 14
🧮 Calculator Tips
- • Check your units (Molarity for concentration)
- • Use scientific notation for small numbers
- • Verify results make sense (pH 0-14)
- • Practice different calculation types