Chemistry : The p-Block Elements

Which of the following statements is not valid for oxoacids of phosphorus? 

• Orthophosphoric acid is used in the manufacture of triple superphosphate

• Hypophosphorous acid is a diprotic acid

• All oxoacids contain tetrahedral four coordinated phosphorus

• All oxoacids contain tetrahedral four coordinated phosphorus

The variation of the boiling point of the hydrogen halides in the order HF >  HI > HBr > HCl. What explains the higher boiling point of hydrogen fluoride?

• The electronegativity of fluorine is much higher than for other elements in the group

• There is strong hydrogen bonding between HF molecules

• The bond energy of HF molecules is greater than in other hydrogens halides

• The bond energy of HF molecules is greater than in other hydrogens halides

In Which of the following arrangement, the given sequence is not strictly according to the property indicated against it ? 

• HF < HCl< HBr < HI : increasing acidic strength

• H₂O < H₂S < H₂Se < H₂Te : increasing pK_a values.

• NH₃ < PH₃ < AsH₃ < SbH₃  : increasing acidic character

• NH₃ < PH₃ < AsH₃ < SbH₃  : increasing acidic character

Which of the following is a polar molecule?

• BF₃

• SF₄

• SiF₄

• SiF₄

Oxidation states of P in H₄P₂O_5, H₄P₂O₆, H₄P₂O₇, are respectively

• +3, +5, +4

• +5, +3, +4

• +5, +4,+3

• +5, +4,+3

The stability of +1 oxidation state among Al, Ga, In and TI increases in the sequence

• Ga<In< Al<Tl

• Al<Ga<In<Tl

• Tl<In<Ga<Al

• Tl<In<Ga<Al

Which of the following oxide is amphoteric?

• SnO₂

• CaO₂

• SiO₂

• SiO₂

Which one of the following molecules contains no pi -bond?

• CO₂

• H₂O

• SO₂

• SO₂

Strong reducing behaviour of H₃PO₄ is due to

• the presence of one -OH group and two P-H bonds

• high electron gain enthalpy of phosphorous 

• the high oxidation state of phosphorus

• the high oxidation state of phosphorus

XeF₂ is isostructural with 

• TeF₂

• ICl^-₂

• SbCl₃

• SbCl₃