0.1 v/v Phosphoric Acid Preparation
Introduction
Phosphoric acid is a strong acid widely used in various industries such as food, pharmaceutical, and laboratory applications. In laboratory settings, phosphoric acid is often used as a solvent, pH adjuster, and cleaning agent. In this article, we will outline the preparation of 0.1 v/v phosphoric acid, which is a commonly used concentration in many laboratory protocols.
Materials
- Phosphoric acid (H3PO4), 85% w/w
- Distilled water
- Volumetric flasks (100 mL or 1000 mL)
- Pipettes (10 mL and 100 mL)
- Balance
Preparation of 0.1 v/v Phosphoric Acid
Step 1: Calculate the Volume of Phosphoric Acid
To prepare 100 mL of 0.1 v/v phosphoric acid, you need to calculate the volume of phosphoric acid required. The concentration of the stock phosphoric acid is 85% w/w, which means 100 mL of the stock solution contains 85 g of H3PO4.
The formula to calculate the volume of phosphoric acid required is:
Volume of phosphoric acid (mL) = (Desired concentration x Desired volume) / Stock concentration
where:
- Desired concentration = 0.1 v/v
- Desired volume = 100 mL
- Stock concentration = 85% w/w
Volume of phosphoric acid (mL) = (0.1 x 100) / 0.85 = 11.76 mL
Step 2: Measure the Phosphoric Acid
Using a pipette, accurately measure 11.76 mL of the stock phosphoric acid into a volumetric flask.
Step 3: Add Distilled Water
Add distilled water to the volumetric flask to reach a total volume of 100 mL. Mix the solution well to ensure homogeneity.
Step 4: Verify the Concentration (Optional)
To verify the concentration of the prepared phosphoric acid, you can use a pH meter or titrate the solution with a strong base such as sodium hydroxide.
Precautions
- Handle phosphoric acid with caution, as it is corrosive and can cause skin and eye irritation.
- Wear protective gloves, goggles, and lab coats when handling phosphoric acid.
- Prepare the solution in a well-ventilated area to avoid inhaling acidic fumes.
Conclusion
The preparation of 0.1 v/v phosphoric acid is a simple process that requires accurate measurement and mixing of the stock phosphoric acid with distilled water. By following these steps, you can prepare a reliable and consistent solution for your laboratory applications. Always exercise caution when handling phosphoric acid and follow proper laboratory safety protocols.
