Aqua-regia is obtained by mixing two different acids in the ratio :

• 1HNO₃: 3HCl

• 2HNO₃: 2HCl

• 1HNO₃: 2HCl

• 3HNO₃: 1HCl

Formula for agate is

• Na₂SiO₃

• K₂O.SiO₂.Al₂O₃

• SiO₂

• CaF₂

53.

Formula of felspar is

• K₂O.Al₂O₃.6.SiO₂

• K₂O₃.Al₂O₃.6Si₂O₂.2H₂O

• Al₂O₃.2SiO₂.2H₂O

• 3MgO.4SiO₂.H₂O

Which one of the following electrolytes is used in Down's process of extracting sodium metal?

• NaCl + KCl + KF

• NaCl

• NaOH + KCl +KF

• NaCl + NaOH

What is the reaction occurring at the anode in Down's process for the extraction of sodium?

• 4OH^- → 2H₂O + O₂ + 4e^-

• Na⁺ + e^- → Na

• 2Cl^- → Cl₂ + 2e^-

• NaOH → Na⁺ + OH^-

When bauxite powder is mixed with coke and reacted with nitrogen at 2075 K, carbon monoxide and X are formed. What is the gas formed when X is reacted with water?

• NH₃

• N₂

• N₂O

• O₂

Observe the following statements regarding purification of bauxite

I. During Hall's process, silica is removed as Si (vapour).

II. Bauxite ore contaminated with Fe₂O₃ is purified in Baeyer's process.

III. During Serpeck's process, AlN is formed.

The correct answeris

• I, II and III are correct

• Only I and II are correct

• Only I and III are correct

• Only II and III are correct

Which one of the followmg is used as an acid flux in metallurgy?

• CaO

• SiO₂

• Na₂CO₃

• SO₂

Which one of the following is the mineral for tin?

• Galena

• Cerussite

• Cassiterite

• Anglesite

Match the following-

The correct answer is-

• A - iv; B - v; C - ii; D - i

• A - iv; B - v; C - i; D - ii

• A - iv; B - i; C - iii; D - ii

• A - ii; B - v; C - iv; D - i