In the lime kiln, the reaction CaCO₃(s) → CaO(s) + CO₂ (g) goes to completion because:

• of high temperature

• CaO is more stable than CaCO₃

• CO₂ escapes simultaneously

• CO₂ is a gaseous product

CaCl₂ is used as

• disinfectant

• desiccating agent

• medicine

• None of these

Dry distillation of calcium acetate and calcium formate forms:

• methanol

• ethanal

• ethanol

• acetone

With cold and dilute sodium hydroxide fluorine reacts to give

• NaF and OF₂

• NaF + O₃

• O₂ and O₃

• NaF + O₂

55.

Which one of the following reactions occur at the anode, in the Castner process of extracting sodium metal ?

• H₂ → 2H⁺ + 2e^-

• 2Cl^- → Cl₂ + 2e^-

• 4OH^- → 2H₂O + O₂ + 4e^-

• Na⁺ + e^- → Na

A mixture of sodium oxide and calcium oxide are dissolved in water, and saturated with excess carbon dioxide gas. The resulting solution...... is It contains ....... :

• basic; NaOH and Ca(OH)₂

• neutral; Na₂CO₃ and CaCO₃

• Basic; Na₂CO₃ and CaCO₃

• Acidic; NaOH and Ca(OH)₂

The compound formed when gypsum is dissolved in aqueous ammonium sulphate solution, is

• CaSO₄.NH₄Cl, H₂O

• CaCl₂.(NH₄)₂SO₄ , H₂O

• CaSO₄.(NH₄)₂SO₄ 2H₂O

• CaCl₂, NH₄Cl.2H₂O

What are the products formed when an aqueous solution of magnesium bicarbonate is boiled?

• MgO, H₂O, CO₂

• Mg(HCO₃)₂, H₂O

• Mg(OH)₂, H₂O

• Mg, CO₂, H₂O

Oxalic acid reacts with concentrated H₂SO₄ to give a mixture of two gases. When this mixture is passed through caustic potash, one of the gase is absorbed. What is the product formed by the absorbed gas with caustic potash?

• K₂SO₄

• K₂HCO₄

• K₂CO₃

• KOH

Exhausted permutit does not contain ...... ion

• Na⁺

• Mg²⁺

• Al³⁺

• Si⁴⁺