ENCE 433 Dr. Alba Torrents

ENVIRONMENTAL ENGINEERING ANALYSIS Fall 1996

Homework Set # 1 SOLUTION

1.

2. It is easy to choose among the first three answers since the stoichiometry is the same. LiOH is the choose since it has the smalest molecular weight, 24 grams/mole. But we need two moles of it(i.e. 48 grams) to react with one mole of CO2. We need only one mole of Mg(OH)2 to do the same job; however its molecular weight is 58 g/mole ans is therefor rejected. Since two moles of Al(OH)3 consumes 3 moles of CO2, 2/3mole of Al(OH)3 or 2/3(78) = 52 g of Al(OH)3 consume 1 mole of CO2. The choose is still LiOH. LiOH was used in Apolo 11 for this purpouse

3. G negative means that the reaction will proceed spontaneously as written. CO2(g) will be formed spontaneously

Answer 2 is correct