The given question is incomplete. The complete question is:
The combustion of propane (C3H8) in the presence of excess oxygen yields
and
When only 2.5 mol of
are consumed in order to complete the reaction, ________ mol of
are produced.
Answer: Thus when 2.5 mol of
are consumed in their reaction, 1.5 mol of
are produced
Explanation:
The balanced chemical equation is:

According to stoichiometry :
5 moles of
produce = 3 moles of 
Thus 2.5 moles of
will produce =
moles of 
Thus when 2.5 mol of
are consumed in their reaction, 1.5 mol of
are produced
Answer:
a) 25%
b) 27.5 g
c) 90%
Explanation:
a) 75% fat-free by weight means 25% of the weight is made by fat.
b) 110 g ___ 100%
x ___ 25%
x = 27.5g
Each hot dog has 27.5g of fat.
c) 9 cal ___ 1 g fat
y ___ 27.5 g fat
y = 247.5 cal
275 cal ___ 100%
247.5 cal ___ z
z = 90%
90 % of the calories come from fat.
I believe the answer is concentration
Sorry if I’m wrong hope this helps
For plato users
the answer is a. O2(l) O2(g)
hope this helps!