More than one option is correct. All of the water-soluble vitamins such as Vitamin C and B vitamins (Thiamin, Riboflavin, Niacin, Pyridoxine, Cyanocobalamin and Pantothenic acid) are generally excreted by the human body through urine if they are in excess. These vitamins are absorbed by the digestive tract into the blood stream, metabolized and then excreted by the kidneys in the urine. Distinctly yellow urine may indicate excessive riboflavin (Vitamin B₂) intake.

Correct Option: E

More than one option is correct. All of the water-soluble vitamins such as Vitamin C and B vitamins (Thiamin, Riboflavin, Niacin, Pyridoxine, Cyanocobalamin and Pantothenic acid) are generally excreted by the human body through urine if they are in excess. These vitamins are absorbed by the digestive tract into the blood stream, metabolized and then excreted by the kidneys in the urine. Distinctly yellow urine may indicate excessive riboflavin (Vitamin B₂) intake.

Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane (CH₄). However, it also includes varying amounts of other higher alkanes (ethane, propane), and a small percentage of carbon dioxide, nitrogen, hydrogen sulfide, or helium.

Correct Option: A

Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane (CH₄). However, it also includes varying amounts of other higher alkanes (ethane, propane), and a small percentage of carbon dioxide, nitrogen, hydrogen sulfide, or helium.

When copper is exposed to air, it reacts with moist carbon dioxide in the air and slowly loses its shiny brown surface and gains a green coat. This green substance is basic copper carbonate (CuCO₃. Cu (OH)₂). The formation of this green coating on the surface of a copper object corrodes it.

Correct Option: B

When copper is exposed to air, it reacts with moist carbon dioxide in the air and slowly loses its shiny brown surface and gains a green coat. This green substance is basic copper carbonate (CuCO₃. Cu (OH)₂). The formation of this green coating on the surface of a copper object corrodes it.

Thee general electronic configuration of group 15 elements (N, P, As, Sb and Bi) is ns²np³. Since Nitrogen has smallest size and greatest electronegativity in the family, it may gain three electrons and attain noble gas configuration, forming nitride N^3- ions. The other members show little tendency to form tri-negative M^3- ions. Their electronegativity is so low that they would generally form covalent compounds even with highly electropositive elements.

Correct Option: A

Thee general electronic configuration of group 15 elements (N, P, As, Sb and Bi) is ns²np³. Since Nitrogen has smallest size and greatest electronegativity in the family, it may gain three electrons and attain noble gas configuration, forming nitride N^3- ions. The other members show little tendency to form tri-negative M^3- ions. Their electronegativity is so low that they would generally form covalent compounds even with highly electropositive elements.

The reaction between benzene and chlorine in the presence of a catalyst such as aluminium chloride gives Chlorobenzene. This reaction is an example of electrophilic substitution reaction since one of the hydrogen atoms on the ring is replaced by a chlorine atom.

Correct Option: B

The reaction between benzene and chlorine in the presence of a catalyst such as aluminium chloride gives Chlorobenzene. This reaction is an example of electrophilic substitution reaction since one of the hydrogen atoms on the ring is replaced by a chlorine atom.