How to use the calculator
- Enter the concentration of your concentrated hydrochloric acid (typically 12M)
- Enter the desired final concentration of the dilute solution
- Enter the final volume you want to achieve in milliliters
- Click the "Calculate" button to determine the volumes needed
- The calculator will display how much concentrated acid to use and how much water to add
Understanding the formula
The calculator uses the dilution formula M₁V₁ = M₂V₂, where:
- M₁ = Initial concentration (mol/L or M) - the concentration of your concentrated HCl
- V₁ = Volume of initial solution needed (mL) - the amount of concentrated HCl to use
- M₂ = Final concentration (mol/L or M) - the desired concentration of your dilute solution
- V₂ = Final volume (mL) - the total volume of your dilute solution
Example
Suppose you need to prepare 500 mL of 0.5 M HCl from a 12 M concentrated solution:
- M₁ = 12 M, M₂ = 0.5 M, V₂ = 500 mL
- Solve for V₁: V₁ = (M₂ × V₂) / M₁ = (0.5 × 500) / 12 = 20.83 mL
- You need 20.83 mL of 12 M HCl
- Add this to enough water to reach a final volume of 500 mL
Important safety considerations
- Always add acid to water, never water to acid
- Dilution processes release heat, so add acid slowly and allow the solution to cool
- Perform dilutions in a properly functioning fume hood
- Use appropriate personal protective equipment (PPE) including acid-resistant gloves, goggles, and lab coat
- Know the location of safety equipment such as eyewash stations and safety showers