The first ionisation potential is maximum for

• B

• N

• O

• Be

462.

A compound X on heating gives a colourless gas. This residue is dissolved in water to obtain Y. Excess CO₂ is bubbled through aqueous solution of Y when Z is formed. Z on gentle heating gives back X. The X is

• CaCO₃

• Ca(HCO₃)₂

• Na₂CO₃

• NaHCO₃

Bleaching action of SO₂ is due to its :

• oxidising property

• acidic property

• basic property

• reducing property

For the second period elements the correct increasing order of first ionisation enthalpy is:

• Li < B < Be < C < O < N < F < Ne

• Li < B < Be < C < N < O < F < Ne

• Li < Be < B < C < O < N < F < Ne

• Li < Be < B < C < N < O < F < Ne

Which of the following is an amphoteric hydroxide?

• Ca(OH)₂

• Mg(OH)₂

• Be(OH)₂

• Sr(OH)₂

Enzymes that utilize ATP in phosphate transfer require an alkaline earth metal (M) as the cofactor. M is :

• Mg

• Ca

• Sr

• Be

Which of the following is soluble in water?

• Br

• Sr

• Mg

• Ba

Which azide is explosive?

• Ba(N₃)₂

• NaN₃

• KN₃

• Mg₃N₂

Match List I with List II and choose correct answerfrom the codes given below

List I	List II
A. NaNO3	(i) Baking soda
B. Na(NH4)HPO4	(ii) Chile salt
C. NaHCO3	(iii)Microcosmic salt
D. Na2CO3 . 10H2O	(iv)Washing soda

• A     B     C     D

  (i)  (ii)  (iii)   (iv)

• A     B     C     D

  (ii)  (iii)   (i)   (iv)

• A     B     C    D

  (iii)  (i)  (ii)  (iv)

• A      B    C    D

  (iv)  (i)  (ii)  (iii)