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⁺

In the hardening stage of plaster of paris, the compound formed is

• CaSO₄

• Orthorhombic CaSO₄.2H₂O

• CaSO₄.2H₂O

• Monoclinic CaSO₄.2H₂O

Sodium is heated in air at 300°C to form X. X absorbs CO₂ and forms Na₂CO₃ and Y. Which of the following is Y ?

• H₂

• O₂

• H₂O₂

• O₃

In which of the following reactions, MgO is not formed?

• Mg + CO₂ →

• Mg + dil. HNO₃ →

• Mg + NO $\stackrel{∆}{\to }$

• Mg + B₂O₃

Which of the following is not correct ?

• Ammonia is used as refrigerant

• A mixture of Ca(CN)₂ and C is known as nitrolim.

• A mixture of Ca(H₂PO₄)₂ and CaSO₄ .2H₂O is known as superphosphate of lime.

• Hydrolysis of NCl₃ gives NH₃ and HOCl.

Observe the following statements:

I. Bleaching powder is used in the preparation of chloroform.

II. Bleaching powder decomposes in the presence of CoCl₃ to liberate O₃.

III. Aqueous KHF₂ is used in the preparation of fluorine.

The correct combination is :

• I, II and III are correct

• Only II is correct

• Only I and III are correct

• Only I and II are correct