Bonding and Structure | OCR A-Level Chemistry A (H432)
Bonding and Structure
- 117 questions
- 10 subtopics
- Module 2: Foundations in chemistry
- Component 01, Component 02 and Component 03
How atoms are held together and what that does to a substance's properties: ionic and covalent bonding, electron pair repulsion and the shapes of molecules, electronegativity and polarity, and the intermolecular forces that decide melting point, solubility and conductivity..
It covers ionic bonding and the properties of ionic compounds, covalent and coordinate bonding, lone pairs, bonding pairs and average bond enthalpy, electron pair repulsion theory, linear and trigonal planar shapes, tetrahedral, pyramidal and non-linear shapes and their bond angles, octahedral shapes, ions, and drawing molecules in three dimensions, electronegativity, polar bonds and polar molecules, permanent and induced dipoles, and hydrogen bonding, simple molecular lattices and why they melt easily and solubility and conductivity of simple molecular compounds.
Sample questions from Bonding and Structure
Answer each one closed book first, then open the answer.
-
Ionic bonding and the properties of ionic compounds
Why do ionic compounds have high melting and boiling points?
Show the answer
A large amount of energy is required to overcome the strong electrostatic attractions between ions throughout the lattice -
Covalent and coordinate bonding
Why are dots and crosses used as different symbols in dot-and-cross diagrams?
Show the answer
To distinguish which atom each electron originally came from in the molecule. -
Lone pairs, bonding pairs and average bond enthalpy
What does a larger average bond enthalpy value indicate about a covalent bond?
Show the answer
It indicates a stronger covalent bond. -
Electron pair repulsion theory, linear and trigonal planar shapes
Why do lone pairs cause greater repulsion than bonding pairs?
Show the answer
Lone pairs are held closer to the central atom and occupy more space, so they exert stronger repulsive forces. -
Tetrahedral, pyramidal and non-linear shapes and their bond angles
Name the molecular shape that results from three bonding pairs and one lone pair.
Show the answer
Pyramidal. -
Octahedral shapes, ions, and drawing molecules in three dimensions
Why is it useful to represent molecular shapes using wedge-and-dash notation?
Show the answer
It allows a two-dimensional diagram to convey the three-dimensional arrangement of atoms in a molecule. -
Electronegativity, polar bonds and polar molecules
What are Pauling electronegativity values?
Show the answer
Pauling electronegativity values are numerical values assigned to elements that allow comparison of their relative abilities to attract bonding electrons. -
Permanent and induced dipoles, and hydrogen bonding
What is another name for induced dipole–dipole interactions?
Show the answer
London dispersion forces.
The 10 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Ionic bonding and the properties of ionic compounds | Recall questions on what an ionic bond is, the lattice, and why ionic compounds melt high, conduct only when molten or dissolved, dissolve in polar solvents and are brittle. | 11 |
| Covalent and coordinate bonding | Recall questions on the covalent bond, how a coordinate bond differs, what an atom needs to be the donor, and reading a dot-and-cross diagram. | 17 |
| Lone pairs, bonding pairs and average bond enthalpy | Recall questions on bonding and lone pairs, what average bond enthalpy measures, and comparing the strength of two bonds from their values. | 8 |
| Electron pair repulsion theory, linear and trigonal planar shapes | Recall questions on the principle behind the theory, why lone pairs repel more strongly, and the bond angles of the linear and trigonal planar shapes. | 10 |
| Tetrahedral, pyramidal and non-linear shapes and their bond angles | Recall questions on methane, ammonia and water, and why their angles fall from 109.5° to 107° and 104.5°. | 15 |
| Octahedral shapes, ions, and drawing molecules in three dimensions | Recall questions on the octahedral angle, applying the theory to ions, and what a wedge, a dashed line and a straight line mean in a three-dimensional drawing. | 14 |
| Electronegativity, polar bonds and polar molecules | Recall questions on the definition and trends of electronegativity, when a bond is polar, and why water has an overall dipole while carbon dioxide has none. | 12 |
| Permanent and induced dipoles, and hydrogen bonding | Recall questions on permanent and induced dipole interactions, what van der Waals covers, the conditions for hydrogen bonding, and why ice is less dense than water. | 9 |
| Simple molecular lattices and why they melt easily | Recall questions on the structure of a simple molecular lattice, why the intermolecular forces are weak compared with the covalent bonds, and the structures of iodine and ice. | 11 |
| Solubility and conductivity of simple molecular compounds | Recall questions on why these compounds dissolve in non-polar solvents but usually not in water, and why they conduct in no state. | 10 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
-
Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
-
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
-
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby sections
OCR A-Level Chemistry A Active Recall Guide
Every section, not just this one. 1,913 questions with their answers.