Question

a chemist prepares a solution of aluminum chloride (alcl₃) by measuring out 47. μmol of aluminum chloride into a 350. ml volumetric flask and filling the flask to the mark with water. calculate the concentration in μmol/l of the chemists aluminum chloride solution. be sure your answer has the correct number of significant digits.

Explanation:

Step1: Convert volume to liters

The volume of the volumetric flask \( V = 350\space mL=\frac{350}{1000}\space L = 0.350\space L\) (since \(1\space L = 1000\space mL\)).

Step2: Use the formula for molarity

The formula for molarity \(c=\frac{n}{V}\), where \(n = 47\space\mu mol=47\times10^{- 6}\space mol\) (since \(1\space\mu mol = 10^{-6}\space mol\)) and \(V = 0.350\space L\).
Substitute the values into the formula: \(c=\frac{47\times 10^{-6}\space mol}{0.350\space L}\)

$$c=\frac{47}{0.350}\times10^{-6}\space mol/L\approx134.29\times10^{-6}\space mol/L = 134\space\mu mol/L$$

Answer:

\(134\space\mu mol/L\)