Explanation:

1)Mass of CO when 210.3 g of Fe produced.
Number of moles of
in 210.3 g=


According to reaction, 2 moles of Fe are obtained from 3 moles of CO, then 3.76 moles of Fe will be obtained from :
of CO that is 5.64 moles.
Mass of CO in 5.64 moles =

2)Mass of CO when 209.7 g of Fe produced.
Number of moles of
in 209.7 g=


According to reaction, 2 moles of Fe are obtained from 3 moles of CO, then 3.75 moles of Fe will be obtained from :
of CO that is 5.625 moles.
Mass of CO in 5.625 moles =

An atomic mass unit (symbolized AMU or amu) is defined as precisely 1/12 the mass of an atom of carbon-12. The carbon-12 (C-12) atom has six protons and six neutrons in its nucleus. In imprecise terms, one AMU is the average of the proton rest mass and the neutron rest mass.
The reaction formula of this is C3H8 + 5O2 --> 3CO2 + 4H2O. The ratio of mole number of C3H8 and O2 is 1:5. 0.025g equals to 0.025/44.1=0.00057 mole. So the mass of O2 is 0.00057*5*32=0.0912 g.
Answer:
300K.
Explanation:
The following data were obtained from the question:
Initial volume (V1) = 300L
Initial temperature (T1) = 200K
Final volume (V2) = 450L
Final temperature (T2) =..?
Since the pressure is constant, the gas is obeying Charles' law.
Using the Charles' law equation, we can obtain the new temperature of the gas as follow:
V1/T1 = V2/T2
300/200 = 450/T2
Cross multiply to express in linear form
300 x T2 = 200 x 450
Divide both side by 300
T2 = (200 x 450)/ 300
T2 = 300K
Therefore, the new temperature of the gas is 300K.