Question

For the reaction shown, compute the theoretical yield of the product (in grams) for each of the following initial amounts of reactants.
Ti (s) + 2 F2 (g) --> TiF4 (s)

7.0 g Ti , 7.0 g F2

2.4 g Ti , 1.5 g F2

0.223 g Ti , 0.282 g F2

Answer 1

Theoretical yield is the maximum amount of product that can be formed from the amount of reagent given.

For each one you need to work out the number of moles of each reagent

From this you can work out the limiting reagent, which is the reagent that is not present in enough quantity to fully react will all of the other reagent

the moles of product formed will the be the amount that forms if all of the limiting reagent is converted to product

Then convert moles of product to mass

1.
Ti(s) + 2F2(g) ----> TiF4

moles = mass / molar mass
molar mass Ti = 47.90 g/mol
molar mass F2 = (2 x 19.0) = 38.0 g/mol
molar mass TiF4 = 47.90 + (4 x 19.0) = 123.9 g/mol

moles Ti = mass / molar mass = 7.0 g / 47.90 g/mol
= 0.146 mole Ti

moles F2 = 7.0 g / 38.0 g/mol
= 0.184 mol F2

Now, equation shows that
1 mol of Ti requires 2 moles of F2 to fully react
Therefore 0.146 mol Ti will require (2 x 0.146) mol of F2 in order to fully react = 0.292 mol of F2

So the amount of F2 required to react all the Ti given is 0.292 moles

but we only have 0.184 mol of F2, which is not enough to fully react with the Ti

That means the F2 is the limiting reagent and Ti is in excess.

The max amount of product possible is if all the limiting reagent is converted to product.

Equation states that
2 moles of F2 --------> 1 mole of TiF4
therefore
1 mole F2 -----> 1/2 moles TiF4
thus 0.184 mole F2 ----> (1/2 x 0.184) mol TiF4
= 0.092 moles TiF4 can be formed from 0.184 mol (7.0g) F2

mass of TiF4 = moles x molar mass
= 0.092 mol x 123.9 g/mol
= 11.4 g (3 sig fig)

Now apply to other two examples....

Answer 2

solved a similar question already with different numbers.. i put the question and the answer.. hope it helps!! :)

For the reaction shown, compute the theoretical yield of the product (in grams) for each of the following initial amounts of reactants.
(equation): Ti(s) + 2F2(g) -> TiF4(s)

0.229g Ti , 0.294g F2

ANSWER:

The balanced equation tells you that 1 mole of Ti can yield 1 mole of TiF4 and that 2 moles of F2 can yield 1 mole of TiF4.

0.229 g Ti = 0.229 g / 47.90 g/mole = 0.00478 moles
0.294 g F2 = 0.294 g / 38.00 g/mole = 0.00774 moles

Which reactant is limiting? F2 should be 2x0.00478 moles, but it is less, so F2 is limiting.

2 moles of F2 yields 1 mole of TiF4, so 0.00774 moles of F2 will yield 0.00774 / 2 = 0.00387 moles of TiF4

0.00387 moles TiF4 x 123.9 g/mole = 0.479 g TiF4