Chemical Bonding AS Level

Phosphorus forms a compound with hydrogen called phosphine, PH₃. This compound can react with a hydrogen ion, H+. Which type of interaction occurs between PH₃ and H⁺?

• dative covalent bond

• dipole-dipole forces

• hydrogen bond

• ionic bond

Which types of bonding are present in ammonium carbonate, (NH₄)₂CO₃? (you can choose more than one answer)

• ionic

• covalent

• co-ordinate (dative covalent)

In which species is there a lone pairs of electrons?

• CH₃

• CH₃⁺

• CH₃⁻

• CH₄

Dicarbon monoxide, C₂O, is found in dust clouds in space. The structure of this molecule is C=C=O. The molecule contains no unpaired electrons.

How many line pairs of electrons are present in a molecule of C₂O?

• 1

• 2

• 3

• 4

What is the correct number of bonds of each type in the Al₂Cl₆ molecule?

• covalent:6 co-ordinate:1

• covalent:6 co-ordinate:2

• covalent:7 co-ordinate:0

• covalent:7 coordinate:1

What are the shapes of the molecules of water and boron trifluoride?

• H₂O=linear ; BF₃=pyramidal

• H₂O=linear ; BF₃=trigonal

• H₂O=non-linear ; BF₃=pyramidal

• H₂O=non-linear ; BF₃=trigonal

The eight species that follow all have covalent bonds. In which pair do the species have different shapes from each other?

• BeCl₂ and CO₂

• CH₄ and NH₄⁺

• NH₃ and BF₃

• SCl₂ and H₂O

Which series shows molecules in order of increasing bond angle?

• CH₄ < BF₃ < NH₃

• H₂O < CO₂ < BF₃

• NH₃ < CH₄ < CO₂

• NH₃ < CH₄ < H₂O

Each of the three species in this question are isolated and gaseous. Which species is planar? (you can choose more than one answer)

• NH₃

• BF3

• CH₃⁺

Sodium borohydride, NaBH₄, and boron trifluoride, BF₃, are compounds of boron. What are the shapes around boron in boronhydride ion and in boron trifluoride?

• BH₄⁺=square planar ; BF₃=pyramidal

• BH₄⁺=square planar ; BF₃=trigonal pyramidal

• BH₄⁺=tetrahedral ; BF₃=pyramidal

• BH₄⁺=tetrahedral ; BF₃=trigonal planar