Quiz: Preparation of Solution

1. You are the manager of a lab stockroom. If there are 10 group ( each group consisting of two students) of students performing an experiment and each group needs 75.0 mL of 2 M HCl, how would you prepare the desired amount of 2M HCl for the entire class using 12M HCl stock solution?

75*10=750ml750*2=12*x or x=750/6=125 ml

2. A stock solution is prepared by placing 10.0 grams of aluminum nitrate (NH4NO3) into a volumetric flask. The aluminum nitrate is then dissolved in water such that the final volume is 250.00 mL. What is the molar concentration of aluminum nitrate?

(10/80)/(250/1000)=0.5M

3. How would you prepare 250.00 mL, 0.125M solution from the above NH4NO3 stock solution?

250*0.125 =0.5*x or x=62.5 ml stock solution required water to be added=250-62.5= 187.5ml water

4. For solutions, dilution factor is defined as D= Ci/Cf or Vi/Vf where Ci=initial concentrationCf=final concentration, Vi=initial volume, Vf=final volume. If you are making 0.25M solution from a stock solution 0.5M what is the dilution factor?

Dilution factor=2