Answer: Option (D) is the correct answer.
Explanation:
Vapor pressure is defined as the pressure exerted by the vapors which are present on the surface of a liquid.
For example, vapor pressure of water at room temperature is 0.0313 atm.
On the other hand, the temperature at which the vapor pressure of a liquid equals atmospheric pressure is known as boiling point.
For example, boiling point of water at room temperature is 
.
Thus, we can conclude that vapor pressure can be described as the pressure exerted by a gas above the surface of its liquid.
Think, does a chemical reaction take place? Do the rocks and/or the water undergo any chemical changes?
Answer:
Gas X
Explanation:
The given reaction can be written in the form of chemical equation as shown below as:
According to law of conservation of mass, the moles of each substance in the reaction must be equal on both reactant and product side.
Also, the question asks for the gas which is diatomic. 
cannot be diatomic as the formula contains 3 atoms.
Between gas X and gas Y , <u>X has to be diatomic for the reaction to balance </u>as:
So you have evidence that the experiment is true or correct.
