Moisture acts as a catalyst in the formation of HCl gas.

The laboratory preparation of $HCl$ includes dehydration of hydrochloric acid with sulphuric acid. It can also be generated by the reaction of sulphuric acid with sodium chloride. 

Metal chloride reaction with sulphuric acid is a double displacement reaction which form a metallic sulphate.

The reaction of chlorine with moist hydrogen gas is explosive in case of direct sunlight.

Conc. $H _2SO _4$ is a very strong drying agent and it is used in purification of hydrogen chloride.

Hydrogen chloride is prepared from chlorine gas and hydrogen gas in the presence of UV light. This reaction is exothermic and the resulting HCl gas is absorbed in deionized water.

Nitric acid $(HNO _3)$ has 3 oxygen atoms in its formula.

When potassium sulphite is treated with dilute hydrochloric acid, sulphur dioxide gas is evolved along with potassium chloride and water.

When concentrated hydrochloric acid reacts with manganese dioxide, chlorine gas as well as manganese(II) chloride and water. 

Iron reacts with hydrogen chloride gas-forming iron$ [II] $ chloride and hydrogen. The reaction is an example of simple displacement reaction.

Explanation :-

Peptization is the process of forming stable colloids by using an electrolyte to break up a precipitate and disperse it into the colloid

$CaO$ and $P _2O _5$ are basic in nature so when $HCl$ is based over them, they will react with $HCl$ and form Salt and water, whereas $H _2SO _4$ and $CO$ are an acidic and hence greater affinity for water. So they can be used to dry $HCl$.

A dry litmus paper will not show any effect in the presence of dry HCL due to the absence of moisture ($H^+$ ions) in the litmus paper, whereas on putting a drop of water, the blue litmus paper immediately turns to red due to the presence of water in it hence presence of hydrogen ions ($H^+$ ions).

Phosphorous pentoxide reacts with $HCl$ to form Phosphorous Oxychloride and metaphosphoric acid.

A gas that is more dense than air can be collected by downward delivery. Examples of gases that can be collected by this method are carbon dioxide, chlorine, HCl, sulphur dioxide.

${ AgNO } _{ 3 }+HCl\rightarrow AgCl+{ HNO } _{ 3 }$

$HCl$ is prepared by heating $NaCl$ with $conc.{ H } _{ 2 }S{ O } _{ 4 }$. But $HI$ cannot be prepared by treating $NaI$ with $conc.{ H } _{ 2 }S{ O } _{ 4 }$. Because  $HI$ is oxidised by ${ H } _{ 2 }S{ O } _{ 4 }$ and $HCl$ is not oxidised by $HI$.

Hence, option $B$ is correct.

Glaber is the scientist who prepared hydrogen chloride in the laboratory by reacting sodium chloride with concentrated sulphuric acid.

$NaCl+H _2SO _4\rightarrow NaHSO _4+HCl$

Sodium bisulphate is a by-product in the above reaction . This is insoluble. Therefore, we further add it with more sodium chloride. This mixture has to be heated to a higher temperature of around 823K. It gives dissolvable sodium sulfate and HCl gas.

$NaHSO _4+NaCl\rightarrow Na _2SO _4+HCl$.

Hence option $A$ is correct.

In the hydrolysis of ICl, the products are HCl + HOI.

Honey bee sting has formic acid in it which causes irritation and burns.

Soda-acid extinguisher uses the reaction between sodium bicarbonate solution and sulphuric acid to expel pressurized water onto a fire. The reaction takes place as follows :-

Sulfuric acid is one of the most important industrial chemicals. It serves as the electrolyte in the lead-acid storage battery commonly used in motor vehicles (acid for this use, containing about 33% $H _2SO _4$ and with specific gravity about 1.25, is often called battery acid).