Answer Happy

a) Patients who have a zinc deficiency can take tablets consisting of a hydrated zinc sulfate, ZnSO4​xH2​O, to treat this problem. A pharmacist heated a 5.073 g sample of hydrated zinc sulfate. After heating, the mass of the remaining anhydrous zinc sulfate was 2.848 g. Use this information to determine the value of x in this hydrated salt. [3 marks] b) In a second experiment to verify the value of x, the pharmacist reacted a 7.579 g sample of the hydrated zinc sulfate with a small excess of powdered magnesium. This should reduce all of the 2n2+ ions to 7n(s) ZnSO4​xH2​O+Mg→Zn+MgSO4​+xH2​O The solid zinc product was dried and weighed, and was found to have a mass of 1.630 g. Use this information to obtain the moles and molar mass of the ZnSO4​×xH2​O in the sample and hence find the value of x. You must show all of your working out. Make sure you use accurate values of molar and atomic masses. [ 6 marks] c) You should find that the values of x obtained by the two experiments do not exactly agree. Give three suggestions to explain this, based on the experimental procedures. (3 marks)