p-Block Elements (Group 15–18)

What is the correct relationship between the pH of isomolar solutions of sodium oxide, Na2O (pH1), sodium sulphide, Na2S (pH2), sodium selenide, Na2Se (pH3) and sodium telluride Na2Te (pH4)?

1. pH1 > pH2 > pH3 > pH4
2. pH1 > pH2 pH3 > pH4
3. pH1 < pH2 < pH3 < pH4
4. pH1 < pH2 < pH3 pH4

Which one of the following orders correctly represents the increasing acid strengths of the given acids?

1. HOClO < HOCl < HOClO3 < HOClO2
2. HOClO3 < HOClO2 < HOClO < HOCl
3. HOClO2 < HOClO3 < HOClO < HOCl
4. HOCl < HOClO < HOClO2 < HOClO3

Which one of the following statements is not true?

1. Among halide ions, iodide is the most powerful reducing agent.
2. Fluorine is the only halogen that does not show a variable oxidation state.
3. HOCl is a stronger acid than HOBr.
4. HF is a stronger acid than HCl.

Which of the following statement is true?

1. Silicon exhibits 4 coordination number in its compounds
2. Bond energy of F2 is less than Cl2
3. Mn(III) oxidation state is more stable than Mn(II) in aqueous state
4. Elements of 15th group show only +3 and +5 oxidation states

Zn gives H2 gas with H2SO4 and HCl but not with HNO3 because

1. Zn acts as oxidising agent when it reacts with HNO3
2. HNO3 is weaker acid than H2SO4 and HCl
3. In electrochemical series Zn is above hydrogen
4. NO3- is reduced in preference to hydronium ion.

Nitrogen forms N2, but phosphorus does not form P2, however, it exists as P4, reason is

1. triple bond present between phosphorus atoms
2. p - p bonding is weak
3. p - p bonding is strong
4. multiple bonds form easily.

Which statement is wrong ?

1. Bond energy of F2 > Cl2
2. Electronegativity of F > Cl
3. F is more oxidising than Cl
4. Electron affinity of Cl > F

Which compound has planar structure?

1. XeF4
2. XeOF2
3. XeO2F2
4. XeO4