A stock bottle of copper sulphate $($heptahydrate$)$ is provided in each lab $($note that this substance is harmful$/$toxic$,$ so you should avoid ingestion or skin contact: clean up any spillages and do not pour any copper sulphate solution down the drains$).$ On the sheet supplied in the exam will be a mass concentration $(\%$w$/$v$)$ and volume of copper sulphate solution to be prepared. In the space below show your calculation to determine what mass of copper sulphate to weight out including units. Using a volumetric flask, make up this solution and measure its absorbance at $650$nm in a spectrophotometer. Record your results below: A$650$ of copper sulphate solution............................................................. $[$Note: after use, pour your solution from the cuvette into the labelled waste pot at the workstation$].$ If the relative molecular mass $($Mr$)$ of copper sulphate $($heptahydrate$)$ is $249\mathrm{.}68,$ what is the molar concentration of the solution you have prepared? Show your calculations and provide units. Use random values to explain how to solve this question or provide steps needed to solve this