Explanation

Pyridine is a six-membered ring with nitrogen in its structure, which makes it a heterocyclic compound.

Explanation

A litmus test is a phrase that originated from the use of litmus paper in chemistry, which changes color in response to certain conditions.

In a broader sense, a litmus test refers to a situation, event, or factor that clearly indicates whether a particular approach, idea, or decision is effective, valid, or acceptable.

It's a decisive test that provides clear evidence or proof.

Explanation

Nitrogen gas (N₂) has a triple covalent bond between the two nitrogen atoms.

This triple bond makes N₂ very stable and unreactive under normal conditions.

Explanation

Oxygen in water (H₂O) has 2 bonding and 2 lone pairs, totaling 4 electron pairs.

Explanation

The pH scale ranges from 1 to 14, with:

• 1-6 being acidic
• 7 being neutral (neither acidic nor basic)
• 8-14 being basic (alkaline)

Explanation

A 100% yield means the actual yield equals the theoretical yield, indicating an ideal reaction.

Explanation

• Sand does not dissolve in water.
• Unlike sugar, glucose, and salt, which are all soluble in water.

Explanation

The catalyst in Friedel-Crafts alkylation is AlCl3 (aluminum chloride).

Explanation

• Hydrogen and Oxygen combining to form water, which is an example of a synthesis reaction: 2H2 + O2 → 2H2O
• In this reaction, two substances (hydrogen and oxygen) combine to form a new compound (water).

Explanation

BF3 (boron trifluoride) is not a nucleophile.

It is a Lewis acid, meaning it accepts electron pairs during reactions rather than donating them.

A nucleophile is a species (atom or group of atoms) that donates a pair of electrons to form a new covalent bond.

Nucleophiles are often negatively charged or have lone pairs of electrons that can be used for bonding.

• H2O (water)
• H2S (hydrogen sulfide)
• NH2