Question

Stoichiometric Calculations

    Balance the following reaction:

    _____ Co + _____ F2 → _____ CoF3

How many grams of fluorine gas would be required to react completely with 10 grams of cobalt metal?   (Show all of your calculations/work.)

How many grams of cobalt fluoride would you expect to be produced?

Write the balanced chemical equation for the reaction between magnesium chloride and sodium phosphate in solution.

Of the two products formed, which one is likely to be a precipitate? Soluble? Site two rules from your “Solubility Rules” that support your answer:

If you measure out 150 grams of sodium phosphate, how much magnesium chloride will you need for a complete reaction?

How many grams of solid material will be produced from this reaction?

Answer 1

Question 1.

A)

Balance Co + F2 = CoF3

Co + 3/2F2 = CoF3

if integers are required

2Co + 3F2 = 2CoF3

b)

How many grams of fluorine gas would be required to react completely with 10 grams of cobalt metal? (Show all of your calculations/work.)

mol of Co = mass/MW = 10/58.93 = 0.16969

ratio is 3/2 so

mol of Fe = 3/2*0.16969 = 0.254535 mol of F2

mass = mol*MW = 0.254535*37.9968064 = 9.6715 g of F2 required

c)

How many grams of cobalt fluoride would you expect to be produced?

ratio is

1 mol of Co = 1 mol of CoF3

then, 0.16969 mol of Co = 0.16969 mol of CoF3

mass = mol*MW = 0.16969 *115.9284046 = 19.671 g of CoF3