Question

a chemist prepares a solution of copper(ii) fluoride (cuf2) by measuring out 4.1 mg of copper(ii) fluoride into a 450. ml volumetric flask and filling the flask to the mark with water. calculate the concentration in mol/l of the chemists copper(ii) fluoride solution. be sure your answer has the correct number of significant digits.

Explanation:

Step1: Calculate molar mass of CuF₂

The molar mass of Cu ($63.55\ g/mol$), F ($19.00\ g/mol$). For CuF₂, $M = 63.55+2\times19.00=101.55\ g/mol$

Step2: Convert mass of CuF₂ to moles

Given mass $m = 4.1\ mg=4.1\times10^{- 3}\ g$. Using $n=\frac{m}{M}$, we have $n=\frac{4.1\times 10^{-3}\ g}{101.55\ g/mol}\approx4.047\times10^{-5}\ mol$

Step3: Convert volume from mL to L

Given volume $V = 450.\ mL = 0.450\ L$

Step4: Calculate concentration

Using $c=\frac{n}{V}$, we get $c=\frac{4.047\times 10^{-5}\ mol}{0.450\ L}\approx8.99\times10^{-5}\ mol/L$

Answer:

$8.99\times 10^{-5}\ mol/L$