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
The best explanation would be A. The reason the balloon is inflated is because its filled with gas, and the gas particles collide with the interior of the balloon to give it its shape.
Precipitation :)
Hope it helps
Light bulbs works by converting electricity into light by using electric currents. it emits electromagnetic radiation
