calculate final volume required to reach 1% solution when 0.2g of sample is predigested with nitric acid 3mL then after 1day, if 1ml sample from this solution is digested in 10ml solution and diluted in 50 mL distilled water.
Either this can't be done or I've misunderstood the question. If the 0.2g sample is pure stuff (and probably it isn't), then the amount in 50 mL = (0.2/3) = 0.06667 g and that is less than 1%.
To calculate the final volume required to reach a 1% solution, we need to follow the step-by-step process given.
Step 1: Predigestion
First, we take 0.2g of the sample and digest it with 3mL of nitric acid. This step allows the sample to dissolve and react with the acid. It's important to note that the concentration of the resulting solution is not given.
Step 2: 1-Day Interval
After 1 day, we move on to the next step, where we take 1mL of the previously digested solution and mix it with 10mL of another solution. Again, the concentration of the solution being added is not provided. We need this information to accurately determine the final concentration.
Step 3: Dilution
Finally, we dilute the mixture from the previous step with 50mL of distilled water. At this point, we have the required information to calculate the final volume required for a 1% solution.
To solve this, we need to know the concentration of the solution used in Step 2. Let's assume it is a stock solution with a known concentration.
Let's denote the concentration of the stock solution as C (in grams/mL). We'll use this value to find the final volume required.
Using the information provided, we can write the equation for dilution:
C1V1 = C2V2
Where:
C1 = concentration of the stock solution (unknown)
V1 = volume of the stock solution used (1mL)
C2 = final concentration (1% or 0.01 g/mL)
V2 = final volume (unknown)
Rearranging the equation:
C1 = (C2 * V2) / V1
Now, substitute the given values:
C1 = (0.01 * V2) / 1
Since C1 is unknown, it's impossible to calculate V2 without the concentration of the stock solution in Step 2.