1. I have 2% NaCl solution. From this I want to prepare a solution to contain 0.1 g of the sodium compound in 2 mL of water.
Thanks
2% NaCl means 2g NaCl/100 ml solution.
0.1g NaCl/2 mL is a 5% solution; therefore, this is not a dilution problem but a concentration problem. So you need to boil away x mL H2O to make the final volume what to make 5%.
2%*(100/x) = 5%
x = ?
To prepare the desired solution, you need to calculate the volume of the 2% NaCl solution that is required.
Let's assume you have the 2% NaCl solution in a 100 mL bottle. This means that in each 100 mL of the solution, there are 2 grams of NaCl.
To find the volume needed, you can set up a proportion using the given information:
(2 grams NaCl) / (100 mL solution) = (0.1 grams NaCl) / (x mL of solution)
Cross-multiplying and solving for x:
x = (0.1 grams NaCl) * (100 mL solution) / (2 grams NaCl)
x = 5 mL of solution
So, you would need 5 mL of the 2% NaCl solution to obtain 0.1 grams of the sodium compound.
Next, to prepare the solution with the desired concentration, you would need to dilute the 5 mL of the 2% NaCl solution with water to a final volume of 2 mL.
Here's how you can do it:
1. Take a clean container with a volume marking to measure the volume accurately.
2. Pour 5 mL of the 2% NaCl solution into the container.
3. Add water, drop by drop, while stirring the mixture until the final volume reaches 2 mL. Make sure the NaCl solution and water are well mixed.
By following these steps, you will have prepared a solution containing 0.1 grams of the sodium compound in 2 mL of water using the 2% NaCl solution.