Understanding ppm
* ppm stands for "parts per million." It's a way of expressing very low concentrations.
* 10 ppm NaNO3 means there are 10 grams of NaNO3 in every 1 million grams of solution.
Materials:
* NaNO3 (sodium nitrate) powder
* Deionized or distilled water
* Accurate balance (can measure to at least 0.01 g)
* Volumetric flask (the size depends on the amount of solution you need)
Calculations:
1. Calculate the mass of NaNO3 needed:
* Since 10 ppm means 10 g NaNO3 per 1 million g of solution, you need to calculate how much NaNO3 to use for your desired volume of solution.
* For example, if you want to make 1 liter (1000 g) of solution:
* (10 g NaNO3 / 1,000,000 g solution) * 1000 g solution = 0.01 g NaNO3
2. Prepare the solution:
* Weigh out the calculated mass of NaNO3 (e.g., 0.01 g) using your balance.
* Add the weighed NaNO3 to the volumetric flask.
* Add a small amount of deionized water to the flask, swirl to dissolve the NaNO3.
* Carefully add more deionized water to the flask until the solution reaches the volume mark.
* Stopper the flask and gently invert several times to ensure thorough mixing.
Important Notes:
* Accuracy: Using a volumetric flask and an accurate balance is crucial for making a precise ppm solution.
* Purity: Use deionized or distilled water to avoid contamination.
* Stability: Store the solution in a clean, airtight container in a cool, dark place to prevent degradation.
* Safety: Always wear appropriate safety gear (gloves, goggles) when handling chemicals.
Example:
Let's say you want to make 500 mL of a 10 ppm NaNO3 solution:
1. Calculate the mass of NaNO3:
* 500 mL of water is approximately 500 g (since the density of water is close to 1 g/mL).
* (10 g NaNO3 / 1,000,000 g solution) * 500 g solution = 0.005 g NaNO3
2. Prepare the solution:
* Weigh out 0.005 g of NaNO3.
* Add the weighed NaNO3 to a 500 mL volumetric flask.
* Add water, dissolve the NaNO3, and make up to the 500 mL mark.
Let me know if you have any more questions.
