If your product had not been dry. would product? Explain your choice. the yield
ID: 982330 • Letter: I
Question
If your product had not been dry. would product? Explain your choice. the yield be higher or lower than the yield based on a dry product? Explain your choice. How many grams of alum can be obtained from 25.0 g of aluminum when the reaction proceeds with 100% yield? How many grams of alum would be obtained if the reaction were to proceed with 75.0% yield? Why was excess KOH used? Explain why boiling the alum solution would help induce crystal formation. Describe three techniques that were used in this experiment. How would you modify the current procedures to produce the product: NaCr(SO_4)_2 12H_2o(s)?Explanation / Answer
Solution.
2. a) This is the formula for alum - KAl(SO4)2*12H2O, the molar mass is 474.4 g/mol;
The molar mass of aluminium is 27.0 g/mol;
Since there is 1 mol of Al per 1 mol of alum, the amount of Al given equals to the amount of alum.
n = m/M = 25.0/27.0 = 0.926 mol;
The mass of alum is m=nM = 0.926*474.4 = 439.3 g.
b) If the percent yield is 75.0 %. the mass fo alum is 439.3*0.75 = 329.5 g.