The volume of the drum after chilled quickly is 3.6 L.
<u>Explanation:</u>
As per the Charles Law, for any gas at constant pressure, volume of the gas is in direct proportion with the temperature measured in Kelvin. As the temperature increases, the gas expands and vice versa.

After chilling the drum, the volume will get reduced and it can be found as,
V2 =
= 
= 3.6 L
Here the drum is chilled quickly, that is temperature is reduced and so the volume also decreases.
Explanation:
Atomic size is defined as the distance between the nucleus and valence shell of an atom. Valence shell is the outermost shell of an atom.
When we move across a period in a periodic table then there will occur a decrease in atomic size of the atoms. But when we move across a group in a periodic table then there will occur an increase in atomic size of the atom.
Hydrogen is a period 1 element, oxygen is a period 2 element, chlorine is a period 3 element and bromine is a period 4 element.
Therefore, given elements are arranged in order of increasing atomic size as follows.
H < O < Cl < Br
I’m assuming in this scenario that 2.5 mols of Fe2O3 is reacting with excess reactant. Based on the balanced equation, you can see that there’s a 1:2 ratio between Fe2O3 and Fe. This means that to find the mols of Fe formed, you need to multiply the mols of Fe2O3 by 2.
2.50mol Fe2O3 * 2mol Fe/1 mol of Fe2O3 = 5.00mols Fe.
<span>Spontaneous reactions need to be discovered first. Also, if reagents are transferred to the other cups used in the tests, it could contaminate them, leading to different colors being seen and the test results being invalid. Doing the reagent tests last ensure that the cups and reagents are only used on the substances that they are intended to.</span>