Which of the following statements are correct for alkali metal compounds ?

(i) Superoxides are paramagnetic in nature.

(ii) The basic strengths of hydroxides increases down the group.

(iii) The conductivity of chlorides in their aqueous solutions decreases down the group.

(iv) The basic nature of carbonates in aqueous solutions is due to cationic hydrolysis.

• (i), (ii) and (iii) only

• (i) and (ii) only

• (ii), (iii) and (iv) only

• (iii) and (iv) only

CaOCl₂ + H₂O → Ca(OH)₂ + X

X + CH₃CHO →  Y

Y + Ca(OH)₂  → CHCl₃

 What is 'Y'?

• CH₃CH(OH)₂

• CH₂Cl₂

• CCl₃CHO

• CCl₃COCH₃

Among the following, which is water insoluble?

• Sodium fluoride

• Potassium fluoride

• Beryllium fluoride

• Magnesium fluoride

274.

Solvay process is used in the manufacture of

• K₂CO₃

• KHCO₃

• Na₂CO₃

• CaCl₂

Assertion (A) -  K, Rb and Cs form superoxides.

Reason (R) - The stability of the superoxides increases from K to Cs due to decrease in lattice energy.

The correct answer is

• Both (A) and (R) are true and (R) is the correct explanation of (A).

• Both (A) and (R) are true but (R) is not the correct explanation of (A).

• (A) is true but (R) is not true.

• (A) is not true but (R) is true.

In photoelectric effect, if the energy required to overcome the attractive forces on the electron, (work functions) of Li, Na and Rb are 2.41 eV, 2.30 eV and 2.09 eV respectively, the work function of 'K could approximately be in eV.

• 2.52

• 2.20

• 2.35

• 2.01

Na₂S₂O₃ reacts with moist Cl₂ to form Na₂SO₄, HCl and X. Which one of the following is X?

• H₂S

• SO₂

• SO₃

• S

Heating chloroform with aqueous sodium hydroxide solution forms-

• sodium acetate

• sodium oxalate

• sodium formate

• chloral

Ni anode is used in the electrolytic extraction of

• Al

• Mg

• Na by Down's process

• Na by Castner's process

Which of the following is not correct?

• LiOH is a weaker base than NaOH.

• Salts of Be undergo hydrolysis

• Ca(HCO₃)₂ is soluble in water.

• Hydrolysis of beryllium carbide gives acetylene.