Solution

Galena (PbS) are sulphide ores. Cassiterite SnO₂ (oxide ore), and Magnetite Fe₃O₄ (oxide ore) are not sulphide ore. The froth flotation process is used to concentrate sulphide ores, based on preferential wetting properties with frosting agent and water.

Halogenation of alkanes will lead to the formation of alkyl halide. In this reaction, if we use Cl₂ in excess, then dichloro and trichloro forms as product and if ethane is used in excess, ethyl chloride forms as major product. So, the reaction takes place as follows:

C₂H₆+Cl₂→C₂H₅Cl+HCl 
(excess)

Solution

Ingestion of excess fluoride, most commonly through drinking water, can cause fluorosis which affects the teeth and bones. Moderate amounts lead to dental effects, but long-term ingestion of large amounts can lead to potentially severe skeletal problems.

Solution

One liter 1N solution of KMnO4? corresponds to 1 g equivalent. In acid medium for oxidation, the equivalent weight of KMnO₄? is one fifth of its molecular mass. It is 15 / 58?=31.6.
Hence, 1 g equivalent of KMnO₄? corresponds to 31.6 g.

Hence, in order to prepare one liter 1N solution of KMnO₄?, 31.6 grams of KMnO4? are required, if the solution to be used in acid medium for oxidation.

Solution

During permanganate tirtrations such as titration of potassium permanganate with oxalic acid, oxalic acid solution is in a conical flask and potassium permanganate solution is in the burette.
As the end point is reached, the solution changes colour to pink as potassium permanganate has intense purple colour. Even a slight excess of it will give pink colour.

Solution

SOLUTION

(CH₃)₂C = CHCH₃?(CH₃)₂CH−CH₂CH₃

The reduced product does not contain a chiral carbon atom and hence is optically inactive. so it is zero.