Examine the reaction C 3 H 8 +5O2—>3CO 2 +4H 2 O. If the reaction starts with 2.5g C 3 H 8 what is the theoretical yield of water ? If the reactant yields 75 % of the theoretical yield of water, how many grams of water were produced?

Theoretical yield = 4.09 g water.

75% yield = 3.07g water.

Explanation:

C3H8 + 5O2 --->  3CO2 + 4H2O

Using atomic masses:

(12 *3 + 8 * 1.008) g C3H8  yield (theoretically) (4* (2*1.008 + 16) g water

44.06g C3H8 yields 72.06g water

So 2.5 g yields  (72.06/44.06) * 2.5

= 4.09 g  water.

If the yield is 75% then it is 4.09 * 0.75

= 3.07 g water.