Yes. In a homogeneous mixture the hydrogen and oxygen are not chemically combined; in water vapor, they are. You can separate a homogeneous mixture of hydrogen and oxygen by physical means, such as by cooling the mixture until the oxygen liquefies. If you cool water vapor you're just going to get liquid water and then ice - not two separate substances. That's because compounds can only be separated into their elements by chemical means.
Benzaldehyde or C6H5CHO would not undergo the aldol condensation because it does not contain an alpha-hydrogen in its structure. Aldol condensation is a type of reaction that happens between an enolate and an aldehyde or ketone leading to a alkene that has a planar structure. The lack of an alpha-hydrogen would not allow for it to undergo such process since it cannot enolize. Benzaldehyde undergoes a nucleophilic reaction known as Claisen-Schmidt condensation. It has somehow same mechanism of the aldol reaction however, the nucleophilic attack on the carbonyl happens even without the alpha-hydrogen but with an enolate that is from a ketone.
<h3><u> Answer</u>;</h3>
= 4.0 L
<h3><u>Explanation;</u></h3>
Boyle's law states that the volume of a fixed mass of a gas is inversely proportional to pressure at a constant temperature.
Therefore; <em>Volume α 1/pressure</em>
<em>Mathematically; V α 1/P</em>
<em>V = kP, where k is a constant;</em>
<em>P1V1 = P2V2</em>
<em>V1 = 0.5 l, P1 =203 kPa, P2 = 25.4 kPa</em>
<em>V2 = (0.5 × 203 )/25.4 </em>
<em> = 3.996 </em>
<em> ≈ </em><em><u>4.0 L</u></em>