To calculate the concentration of your essential oil solution in mg/mL after dilution, follow these steps:

1. Determine the amount of essential oil:

You have 0.2 mL of essential oil weighing 200 mg.

2. Dilute to the final volume:

You want to dilute this 0.2 mL of essential oil to a final volume of 5 mL.

3. Calculate the concentration:

The concentration C in mg/mL can be calculated using the formula:

C = Amount of essential oil (mg) \ Final volume (mL)

Substitute the values:

C = 200 mg / 5 mL

Perform the division:

C = 40 mg/mL

So, the concentration of the diluted essential oil solution is 40 mg/mL.

You may use the web tool to calculate

https://www.alfa-chemistry.com/solution-dilution-calculator.htm

https://www.alfa-chemistry.com/mass-molarity-calculator.htm