# Finding the concentration from a dilution

This must be a very basic question but I have gotten confused over it. How would I find the concentration of each component of the reaction for each experiment from this data? I am guessing it can’t be the concentrations given, is that for some stock solution? Solving one out of the four would be good enough to understand the concept behind this. Therefore, I shall explain the first experiment and the concentrations of the components in the solution produced.

In experiment 1 all four are added in equal quantities. Finding the total volume, we get the total volume

$$V_\text{tot} = \pu{4 ml}.$$

Assuming the amount of $$i$$th solute to be denoted by $$n_i,$$ its molarity $$c_i$$ can be found as

$$c_i = \frac{n_i}{V_\mathrm{tot}}.$$

Now, we add $$\pu{1 ml}$$ of $$\pu{2.0 M}$$ acetone. This is equivalent to saying we add $$1/1000$$ of $$\pu{2 mol}$$ of acetone. Therefore we add $$\pu{2 mmol}$$ (millimoles) of acetone.

This means that we have $$\pu{2 mmol}$$ of acetone in $$\pu{4 mL}$$ of water. Using the formula for molarity we get that acetone is in $$\pu{0.5 M}$$ in solution.

Hope you can follow on for the other parts as well, the concept remains the same.