Alum Experiment POSTLAB QUESTIONS Name Consider one of the

Alum Experiment POST-LAB QUESTIONS Name: . Consider one of the steps in the reaction process o the experiment we carried out: 2 Als) + 2 KOHuat 6 HSU) 2 K+(aq) + 2 Al(OH)4-(aq) + 3 Hap If 10.0 g of hydrogen gas were formed in the reaction, what mass of aluminum would have had react? 2. Consider the overall reaction for the synthesis of potassium alum (aq) If 15.0 g of aluminum were reacted under the proper conditions and a 72.0 % yield were achieved, what mass of alum would have been formed?

Solution

1. 2Al(s) +2KOH(aq)+6H2O(l)--->2K⁺(aq)+2Al(OH)4^-+3H2(g)

As per the reaction-.

3 moles of H2 is formed by = 2 moles of Al

3mol*2.01g/mol of H2 is formed by = 2mol*26.99g/mol of Al

1g of H2 is formed by = 2mol*26.99g/3mol*2.01g/mol of Al

= 8.95g of Al

10g of H2 is formed by = 8.95*10g of Al = 89.5g of Al

Mass of Al = 89.5g