I. An alum is a double salt consisting of a monovalent cation, a trivalent catio
ID: 576021 • Letter: I
Question
I. An alum is a double salt consisting of a monovalent cation, a trivalent cation, and two sulfate homs with 12 waters of hydration (waters of crystallization) as part of the crystalline structure . Are the 12 waters of hydration used to calculate the theoretical yield of the alum? Explain. b. The 12 waters of hydration are hydrated (strongly attracted) to the metal ions in the crystalline alum structure. Are the water molecules more strongly hydrated to the monovalent cation of the trivalent cation? Explain. hat might you expect to happen to the alum if it were heated to a high temperature? Explain e. W ium alum, synthesized in this experiment, has the formula KAI(So) 12 H,O: written as a double salt, however, its formula is K SO Al(SOJ24 H.O. Refer to Table 15.1 and write the formula of a. chrome alum as a double salt. b. ferric alum as a double salt. 11c a. Experimental Procedure, Part A.3. What is the technique for securing a piece of filter paper into a i funnel for gravity filtration? Experiment 15 71Explanation / Answer
1(a). The general formula of given alum is MT(SO4)3.12H2O where M is a monovalent cation and T is a trivalent cation.
Yes,to calculate the theoretical yield of the alum the 12 water molecules are also considered because these water molecules are the part of alum (forms the complete molecular formula) and hence to calculate the molecular weight of the alum these are also added.
1(b).Water will be hydrated strongly to the trivalent cation because as the we water is a polar compound and will be attracted towards the more charged cation in compare to less charged cation.
1(c).If we heat the alum at high temperature it will loose its water of hydration as vapours :
MT(SO4)3.12H20 (heat) = MT(SO4)3 + 12H2O(vapour)
Because these water of hydration are loosoly bound and water is a volatile compound which evaporates at high temperature.