Free Chemical bonding questions for AS Level Chemistry (9701), part of Physical chemistry. Each question has the answer and the marking points an examiner would look for.
Generate a full Chemical Bonding worksheet →All Physical chemistry questionsHydrogen fluoride has a much higher boiling point than hydrogen chloride.
1 HF has a larger Mr than HCl.
2 F is more electronegative than Cl.
3 HF molecules form hydrogen bonds with each other.
Which statements are correct?
Answer: B
Which statement describes electronegativity?
Answer: A
How many σ bonds and π bonds are there in a molecule of propene, CH2=CHCH3?
| σ bonds | π bonds | |
|---|---|---|
| A | 7 | 1 |
| B | 8 | 1 |
| C | 8 | 2 |
| D | 9 | 1 |
Answer: B
Explain the trend in boiling points of the hydrogen halides HF, HCl, HBr and HI.
Explain the trend from HCl to HI.
Explain why HF has an anomalously high boiling point.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | more electrons, stronger London forces more electrons down the group B1 stronger instantaneous dipole–induced dipole forces B1 | 2 |
| (b) | hydrogen bonding HF molecules form hydrogen bonds B1 which are stronger than the other intermolecular forces B1 | 2 |
Ammonia, NH₃, and boron trifluoride, BF₃, have different shapes.
Predict the shape and bond angle of each molecule, explaining your answers using VSEPR.
Explain why ammonia is very soluble in water.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | NH₃ trigonal pyramidal 107°; BF₃ trigonal planar 120° NH₃: 3 bond pairs + 1 lone pair B1 trigonal pyramidal, about 107° B1 BF₃: 3 bond pairs, no lone pairs B1 trigonal planar, 120° B1 | 4 |
| (b) | hydrogen bonds with water ammonia forms hydrogen bonds with water molecules B1 lone pair on N and δ+ H B1 | 2 |
This question is about the shapes of molecules and intermolecular forces.
Draw the shape of a molecule of H₂O, name the shape and state the bond angle.
Explain, using VSEPR theory, why the bond angle in NH₃ is smaller than in CH₄.
Define electronegativity.
Explain why CO₂ has polar bonds but is a non-polar molecule.
Explain why water has a much higher boiling point than hydrogen sulfide, H₂S.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | bent (non-linear); 104.5° correct 3D shape drawn with lone pairs shown B1 bent (non-linear) B1 104.5° B1 | 3 |
| (b) | lone pair repels more strongly than bonding pairs; bonds pushed closer, 107° vs 109.5° NH₃ has three bonding pairs and one lone pair B1 lone pair–bonding pair repulsion is greater than bonding pair–bonding pair repulsion B1 so the H–N–H angle is reduced from 109.5° to 107° B1 | 3 |
| (c) | power of an atom to attract the bonding electrons in a covalent bond the power of an atom to attract the pair of electrons in a covalent bond towards itself B1 | 1 |
| (d) | O more electronegative; linear, dipoles cancel C=O bonds are polar since O is more electronegative B1 the molecule is linear so the bond dipoles cancel B1 | 2 |
| (e) | hydrogen bonds between water molecules; O very electronegative with lone pairs; stronger than van der Waals in H₂S water forms hydrogen bonds between molecules B1 O is highly electronegative and has lone pairs that attract δ+ H on neighbouring molecules B1 H₂S has only weaker van der Waals forces (permanent dipole), needing less energy to overcome B1 | 3 |
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Meet Riyaz →Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in