Answer to Question #19232 in Inorganic Chemistry for DeAnna ODell

Question

A student mixed a cobalt cloride solution with a potassium arsenate solution a solid was observed. How many grams of solid can be formed from mixing 35.6mi. of 0.342 M cobalt chloride solution with 35.8 ml. of .251 M potassium arsenate solution? Which reactant is in excess and by how many milliliters? Which substance is the limiting reactant?

Answer 1

n of CoCl₂--?
in excess(0.01218-0.00899/2 = 0.007685 mol (22.46 ml))

0.342mol - - - 1000ml
x mol -- --- ----------35.6ml

x = 0.01218 mol

n of KH₂AsO₄ --? is the limiting reactant

0.251mol - - -1000ml
y mol -----------35.8ml

y = 0.00899 mol


2KH₂AsO₄+CoCl₂ =Co(H₂AsO₄)₂ + 2KCl