Answer:
Initially
of nitrogen dioxide were in the container .
Explanation:
Volume of the container at low pressure and at room temperature =
Number of moles in the container = 
After more addition of nitrogen gas at the same pressure and temperature.
Volume of the container after addition = 
Number of moles in the container after addition=
Applying Avogadro's law:
(at constant pressure and temperature)



Initially
of nitrogen dioxide were in the container .
It’s is 130 that is the answer!!!!
The compound Fe(NO2)2 is Iron (II) Nitrite.
Hope I could help :)
Answer:
C3H8 + 5O2 => 3CO2 + 4H2O
Explanation:
Hydrocarbon combustion is the reaction between a hydrocarbon and O2 producing CO2 and water.
C3H8 + O2 => CO2 + H2O
First we balance the C and H.
C3H8 + O2 => 3CO2 + 4H2O
Now we balance O for the answer!
C3H8 + 5O2 => 3CO2 + 4H2O