A student adds $37.4~\mathrm{ml}$ of a $50.0~\mathrm{ppm}$ solution to a $100~\mathrm{ml}$ volumetric flask and dilutes to the mark. What is the concentration of the diluted solution?
- $13.7~\mathrm{ppm}$
- $7.5~\mathrm{ppm}$
- $37.4~\mathrm{ppm}$
- $23.6~\mathrm{ppm}$
I used $$M_1V_1 = M_2V_2$$ which worked for all the others and I assumed would work for this considering I had all of the variables except for the 2nd concentration, but those calculations gave me $18.7~\mathrm{ppm}$, which is not an answer choice.