Chemistry Test - 31

The ring structure of glucose is formed through the creation of a hemiacetal.

This occurs when the hydroxyl group on carbon 5 reacts with the aldehyde group on carbon 1.

Key points about this reaction include:

• The reaction leads to the formation of a ring structure, specifically a six-membered ring known as a pyranose.
• The conversion to a hemiacetal is crucial for the stability and functionality of glucose.
• This structural change influences how glucose interacts with other molecules in biological systems.

Glucose is a type of sugar known as a monosaccharide.

A monosaccharide is the simplest form of carbohydrate, consisting of a single sugar unit. Here are some key points about glucose:

• Basic unit: It is the most basic form of carbohydrate.
• Energy source: Glucose serves as a primary energy source for living organisms.
• Structural role: It can also play a role in forming larger carbohydrates.

The inner transition elements are the elements in which the added electrons go to (n-2) f-orbitals. These include lanthanoids and actinoids. In lanthanoids, the added electron goes to 4f orbital and in actinoids, the added electron goes to 5f orbital.

The second series includes the elements yttrium (symbol Y, atomic number 39) to cadmium(symbol Cd, atomic number 48).

The correct answer is option  B

Ln(III) compounds are coloured due to the f−f transitions in the lanthanide but the colour is fainter as compared to the d−d transitions in transition metals.

Let the oxidation state of pt be x.

Oxidation state of cl is -1.

So x + 0 – (1*3) must be equal to -1 since the charge of the whole compound is -1.

x + 0 – (1*3) = -1

x -3 = -1

x = -1 + 3

x = +2

So the oxidation state of platinum is +2.

Secondary is due to legend there are mono deadened legend 

then 1×4= 4

Pt(NH₃)₂CI₄] is neutral complex and no ions are formed in aqueous solution.

K,(PtCl₆] → 2K⁺ + [PtCI₆]^2-

It does not have Cl^- ion toffive precipitate of AgCI.

Mohr's salt is a doub le salt and it will give test for Fe²⁺ ion. It dissociates into simple substances or ions completely when dissolved in water.

tert-Butyl alcohol is the most heavily branched isomer and is tightly packed compared to the others. This decreases the effective surface area of the alkyl part which is hydrophobic in nature.

Phenol’s -OH group activates the aromatic ring, making it highly reactive toward electrophilic aromatic substitution like bromination. Unlike benzene, which requires Lewis acids (e.g., FeBr₃) to generate Br⁺, phenol reacts directly with Br₂ in a non-polar solvent like CS₂, which controls the reaction and favors monobromination (e.g., 4-bromophenol).

- B, C, D: FeBr₃, AlCl₃, and BF₃ are Lewis acids needed for less reactive aromatics like benzene, not phenol.

Correct option: A