Common Chemical Compounds and Reactions

Chalk powder is insoluble in water while salt completely dissolves, so adding water to each substance will clearly differentiate them - the chalk powder will remain as a solid residue at the bottom while salt will disappear into the water. Particle size observation and sieving won't work reliably since both can have similar particle sizes, and heating would just evaporate water from salt but leave both as solids.

Salt (NaCl) dissolves fastest in water because it's an ionic compound that readily dissociates into Na+ and Cl- ions when in contact with water. Sugar takes longer to dissolve, baking powder is a mixture that reacts before fully dissolving, and chalk powder is mostly insoluble in water. The ionic nature of salt makes it highly soluble with quick dissolution kinetics.

This is the correct option. Nitric acid solution and potassium hydroxide solution are strong electrolytes. They both contain lots of ions in them.

Natrium is the Latin name of sodium.

The head of a safety match contains an oxidizing agent, typically potassium chlorate (KClO3), which provides oxygen to sustain combustion when the match is struck. Phosphorus pentoxide (P2O5) is not used on match heads. Potassium chloride (KCl) is different from potassium chlorate.

In a safety match, the striking surface contains red phosphorus. When the match is struck, friction converts red phosphorus to white phosphorus, which ignites and initiates the combustion of potassium chlorate and antimony trisulfide on the match head. Red phosphorus on the side surface ignites FIRST, then transfers heat to the match head.

Safety match heads contain antimony trisulfide (the fuel), potassium chlorate (the oxidizing agent), and powdered glass (abrasive). The striking surface contains red phosphorus. When the match is struck, friction generates heat, the red phosphorus converts to white phosphorus, which ignites the potassium chlorate, starting the combustion of antimony trisulfide.

Sodium hydroxide is an alkali.

Phosphorus (specifically red or white phosphorus) is used in matchbox industries, particularly on the striking surface of safety matches. When the match head is rubbed against this surface, the friction generates enough heat to ignite the phosphorus, which then ignites the match head. Sulphur is sometimes present in the match head itself, but the key material on the striking surface is phosphorus.

Jeweller's borax (Na₂B₄O₇. 5H₂O) is the borax,  which contains five molecules of water of crystallisation.

The Solvay process or ammonia-soda process is the major industrial process for the production of soda ash (Sodium carbonate).  The principal byproduct of the Solvay process is calcium chloride (CaCl₂) in aqueous solution.

Minute quantities of alum are added to facilitate sedimentation.

Yes, on blowing air in a glass full of limewater through a drinking straw, it is observed that the limewater turns milky. This shows that carbon dioxide is released during exhalation.

Yes, it is correct. ORS is a solution of 6 tsp of sugar and 1/2 tsp of salt in 1 litre of water. It is given to diarrhoea patient to compensate for the loss of fluids in the body.