Alum | MCQs

Explanation

Bauxite is the most important ore of aluminum which contains only 30–54% alumina.

The rest is a mixture of silica, various iron oxides,

and titanium dioxide along with trace amounts of zinc, phosphorous, nickel, vanadium etc.

Explanation

Aluminium has a valency of 3 because it loses three electrons to achieve a stable electron configuration.

Its atomic number is 13.

Its electron configuration is 2, 8, 3.

This means it donates three electrons to form Al³⁺ ions.

Explanation

Copper has higher conductivity, strength, and corrosion resistance, leading to fewer failures and repairs.

Its durability and long lifespan reduce replacement and maintenance costs over time.

Explanation

Aluminium burns in oxygen with a brilliant white flame, producing aluminium oxide (Al₂O₃).

This reaction is highly exothermic.

It is often seen in thermite reactions and metal combustion demonstrations.

Explanation

The atomic mass of aluminum (Al) is 26.98, which is approximately 27.

This is the most common isotope of aluminum, which has an atomic number of 13.

Explanation

Explanation

Bauxite is the most common aluminum ore. Approximately 98% of primary aluminum production is based on bauxite

Explanation

Amphoteric nature​​ Aluminium oxide is an amphoteric substance, meaning it can react with both acids and bases

It is a chemical compound of aluminium and oxygen with the chemical formula Al2O3.

Explanation

Explanation

Baeyer's method is used for the purification of bauxite with excess silica.

It involves treating bauxite with sodium hydroxide.

It dissolves the alumina, leaving the silica behind.