Question

a chemist prepares a solution of mercury(i) chloride ($hg_2cl_2$) by measuring out 0.000164 μmol of mercury(i) chloride into a 50 ml volumetric flask and filling the flask to the mark with water. calculate the concentration in mmol/l of the chemists mercury(i) chloride solution. be sure your answer has the correct number of significant digits.

Explanation:

Step1: Convert micromoles to millimoles

We know that $1\ \text{mmol}=1000\ \mu\text{mol}$. Given $n = 0.000164\ \mu\text{mol}$, so $n$ in mmol is $n=\frac{0.000164}{1000}=1.64\times 10^{-7}\ \text{mmol}$.

Step2: Convert volume from mL to L

We know that $1\ \text{L} = 1000\ \text{mL}$. Given $V=50\ \text{mL}$, so $V$ in L is $V=\frac{50}{1000}=0.05\ \text{L}$.

Step3: Calculate the concentration

The formula for concentration $C=\frac{n}{V}$. Substituting $n = 1.64\times 10^{-7}\ \text{mmol}$ and $V = 0.05\ \text{L}$ into the formula, we get $C=\frac{1.64\times 10^{-7}\ \text{mmol}}{0.05\ \text{L}}=3.28\times 10^{-6}\ \text{mmol/L}$.

Answer:

$3.28\times 10^{-6}\ \frac{\text{mmol}}{\text{L}}$