The efficiency of a boiler is found to decrease when boiler scales are formed. Suggest a suitable chemical method to prevent the scale formation.

The efficiency of a boiler is found to decrease when boiler scales are formed.Write the chemistry of scale formation?

Benzamide (C_6H_5CONH_2) on heating with bromine and NaOH gave a compound A which is soluble in dilute acid. When A is warmed with chloroform and alc KOH, B is formed which has an unpleasant odour. Using chemical equation represent the formation of B from A.

Hydrogen is the most abundant element in the universe, but in free state it is almost not found in earth's atmosphere. suggest any three methods for the preparation of H_2 gas by selecting suitable substance given below.

The element Cu with atomic number 29 undergoes chemcial reaction to formation with oxidation number +2: Write downthe chemical formula of one compound formed when this element re-acts with chlorine ("17CI) .