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:
D
Explanation:
One of the properties of metals is their abilities to form a stable compounds by losing electron(s). Metals form positive ions (cations) when they lose electron(s).
Answer:
Your question is half unfinished, regarding the chromium III oxide the correct option that expresses the inorganic formula of said compound is "A"
Explanation:
In the reaction an initial salt reacts giving as product water vapor, nitrogen gas and an oxide that is chromium oxide.
Chromium oxide is an oxide that adopts the structure of corundum, compact hexagonal. It consists of an anion oxide matrix with 2/3 of the octahedral holes occupied by chromium. Like corundum, Cr2O3 is a tough, brittle material.
It is used as a pigment, green in color.
By use of combined gas law
P2= T2P1V1/V2
v1=5L
P1=540 torr
T1=25+273=298k
V2=15 L
T2=32+273=305 k
P2 is therefore=( 305k x 540 torr x5 L) /( 15L x 298)= 184.23 torr