Answer:
2.5 L
Explanation:
The stoichiometric ratio of N2 to N2O4 is 1:1
Answer:
MOLAR MASS = 32 g/mol
Explanation:
Condition of standard temperature and pressure(STP) are as follow:
Temperature = 273 K
Pressure = 1 atm (or 100000 Pa)
Here atm is atmosphere and Pa is Pascal
STP conditions arte used for measuring gas density and volume using Ideal Gas Law.Here 1 mole of ideal gas occupies 22.4 L of volume.
According toi Ideal Gas Equation :
PV = nRT
where P = pressure, n= number of moles, V = volume ,R= Ideal Gas Constant and T= temperature

From question:
V=280 ml = 0.28 L
P = 1 atm
R=0.08205 L atm/K mol
T=273 K
Putting values in above formula :

n = 0.0125 moles
Now 

given mass = 0.4 g (given)

On solving we get:
Molar mass = 32 g/mol
Well countries near the quitter of warmer than countries than the poles. So the mystery island would probably be near the equator near Florida or in Florida
Well, its a very simple process actually. Here is how it works;
When molecular hydrogen, also known as H2, and oxygen, also known as O2, are combined and are able to react together, energy is released and the molecules of the hydrogen and the oxygen. These can combine to form either water or hydrogen peroxide, depending on how the chemicals mix.
I hope I made your day a little easier,
Have a great day and happy Halloween!