Sorry this will probably be pretty long.
So think of the "control" as being something you yourself add to increase or decrease the effects in an experiment.
I'll give you an example so it is not as confusing.
Say you have decided to make an experiment on plants. Which plant can grow the fastest on which type of liquid? What is being added to this experiment? The liquid! Or all of the liquids you used. Like if you used Coke, Lime Gatorade, Orange Gatorade, and Water. Each drink will EFFECT each plant differently.
Hope I was of any hope?
The mole ratio is 4 NO2 to 3 O2; 4:3
i think the answer is C but don't take my word for it
Answer:
Vf = 1.22 mL
Explanation:
If we assume that the pressure is constant and the number of moles does not change, we can say that the volume of the gas is modified in a directly ratio, to the Absolute Temperature.
Let's convert the values:
91°C + 273 = 364K
0.9°C + 273 = 273.9K
Volume decreases if the temperature is decreases
Volume increases if the T° increases
V₁ / T₁ = V₂ / T₂ → 1.63mL /364K = V₂ / 273.9K
V₂ = (1.63mL /364K) . 273.9K → 1.22 mL