The answer is gonna be the last one :)
I believe that is a plant called Wisteria.
Explanation:
21. The given molecule for cracking is tetradecane.
On cracking it forms one mole of decane (C10H22) and two moles of ethene gas.
The chemical equation is shown below:

22. The essential condition for the formation of an ester is the reaction of alcohol and acid in presence of concentrated sulfuric acid.
Thus among the given options, the first option is the correct one.
23. Isomers of butanol are shown below:
It is 2-butanol.
The position of -OH group changes to the second carbon.
The oxidation number sulfur in H₂S is -2.
A compound's total number of oxidations must be zero.
The two hydrogen atoms in the chemical hydrogen sulfide, H₂S, each have an oxidation number of +1, making a total of +2. As a result, the compound's sulfur has an oxidation number of -2, and the total number of oxidations is 0.
Assume that the sulfur atom in H₂S has an oxidation number of x.
S be x.
Now,
2+x=0
⇒x=−2
<h3>What is oxidation number?</h3>
The total number of electrons that an atom either receives or loses in order to create a chemical connection with another atom is known as the oxidation number, also known as the oxidation state.
Depending on whether we are taking into account the electronegativity of the atoms or not, these phrases can occasionally have a distinct meaning. Coordination chemistry commonly makes use of the phrase "oxidation number."
<h3>What distinguishes an oxidation number from an oxidation state?</h3>
In contrast to the oxidation state, which indicates how oxidised an atom is in a molecule, the oxidation number describes the charge that the core metal atom will retain once all ligands have been removed.
To know more about oxidation number:
brainly.com/question/13182308
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Answer: Kw (mol2 dm-6):1.008 x 10-14 pH:7.00
Explanation: