Explanation

The compound that is not a dehydrating agent is CaCl2 (hydrated calcium chloride). 

While anhydrous CaCl2 (calcium chloride) is a dehydrating agent, hydrated CaCl2 (calcium chloride with water molecules attached) does not have the same ability to absorb water. 

Explanation

The discomfort of breathing in an unpressurized cabin is due to a Low pressure of O2.

Explanation

Among the halogen acids (HF, HCl, HBr, and HI), HI (hydroiodic acid) is the strongest.

The strength of an acid is determined by the ease with which it can donate a hydrogen ion (H+).

The H-I bond is the weakest of the halogen acid bonds, allowing HI to readily dissociate in water and release H+ ions. 

Explanation

When zinc reacts with dilute sulfuric acid, it forms zinc sulfate (ZnSO₄) and releases hydrogen gas (H₂).

The reaction is:

Zn + H₂SO₄ → ZnSO₄ + H₂↑

Explanation

• Phenolphthalein is a pH indicator that changes color in response to changes in acidity or basicity.
• In an acidic medium, it is colorless, and in a basic medium, it turns pink.

Explanation

Let the two charges be:

• $+q$ at one end

• $-q$ at the other end

• Distance between them = $2d$

• Midpoint = distance $d$ from both charges

The electric potential at a point due to a charge:

V= kq/r​

So, at the midpoint:

• Potential due to $+q$: +kq/ d​

• Potential due to $-q$: $-frac{kq}{d}$

Vnet​=kq/d​−kq​/d=0

Explanation

Chloroform is classified as a possible human carcinogen, particularly linked to liver and kidney cancer with prolonged exposure.

It affects the liver by causing cellular damage.

It has been shown to induce tumors in animal studies.

Explanation

Tollen's reagent detects aldehydes, which reduce Ag⁺ to metallic silver (silver mirror test).

CH₃CHO is an aldehyde, so it reacts with Tollen’s reagent; the others are ketones or acids, which do not.

Explanation

The Cannizzaro reaction is a disproportionation reaction where a non-enolizable aldehyde undergoes simultaneous oxidation and reduction.

One molecule of aldehyde is oxidized to a carboxylic acid, and another is reduced to an alcohol.

Explanation

Ethanol (C₂H₅OH) is oxidized to ethanoic acid (CH₃COOH) using oxidizing agents like acidified potassium dichromate (K₂Cr₂O₇).

This chemical reaction involves the gain of oxygen or loss of hydrogen, which defines oxidation.