Course

AS Chemistry: Structure, Bonding and the Mole (9701)

Name: AS Chemistry: Structure, Bonding and the Mole (9701)
Price: 2199 BDT

9701 topics 1 to 4, the half of AS chemistry where nothing reacts yet: what a substance is made of, and how much of it you have. Electrons decide the first, the mole counts the second.

56 lessons5h 33mEnglish

What you'll learn

Write an electron configuration in subshells, and treat ionisation energies as the evidence for it rather than a separate fact to recall
Read an ionisation energy graph and say which jump shows a new shell has been reached
Set out mole, empirical formula, limiting reagent, titration and gas volume calculations the way a 9701 examiner marks them
Predict the shape and bond angle of a molecule from electron pair repulsion, lone pairs included
Decide whether a molecule is polar, and keep a polar bond apart from a polar molecule
Explain melting point, hardness or conduction from the structure, which is what the explain marks are for
Use pV = nRT with units that agree, and name the assumption a real gas breaks first

Requirements

O Level or IGCSE chemistry: the formula of a common ion, and how to balance an equation
O Level chemistry: electrons in shells, and reading a group and a period off the table
Comfortable with standard form, ratio and percentage, and rearranging a formula
Able to read a value and a trend off a graph, including one with a logarithmic axis
A periodic table and a calculator beside you

Course content

56 lessons · 5h 33m

1.1-1.4 · Atomic structure

Protons, neutrons and electrons, then isotopes and relative atomic mass, then the orbital model that replaces the shell picture. Ends on ionisation energy, which is the evidence that the shells and subshells are real.

0/11

What the proton number decides

Predict the outer shell of phosphorus, then separate proton number from nucleon number.

Preview6m 2.

Which particle bends most

Relative charge and relative mass, read off the deflection of three particles.

Preview6m

Why chlorine is 35.5

Isotopes, and the weighted mean that gives a relative atomic mass no atom actually has.

An orbital is not an orbit

Decide whether a 2s cross-section is solid, then meet the radial node.

Three p orbitals, six electrons

Work out how many p orbitals there must be before you rotate one.

Why 4s fills before 3d

Build the configuration of iron one subshell at a time, and see which one empties first.

The definition that earns the mark

Sodium or chlorine: choose which holds its outer electron harder, then learn the wording.

Where the big jump comes

Magnesium loses twelve electrons. Predict the jump, then deduce a group from it.

The climb with two dips

Sketch the Period 3 graph first, then explain aluminium and sulfur by subshell.

10.

Distance and shielding beat charge

Three factors control every ionisation energy. Decide which one wins going down a group.

11.

One exam question, end to end

Seven marks, four parts, no options: deduce the group and the proton number, then explain the jump.

2.1-2.4 · Atoms, molecules and stoichiometry

The mole as a count, and every calculation that hangs off it: molar mass, percentage composition, limiting reagent, yield, concentration, titration and gas volume. The chapter a 9701 candidate uses in every paper.

0/17

The equation counts moles, not grams

Predict how much water four moles of hydrogen can make, then meet the Avogadro constant.

Preview6m 2.

Grams per mole, straight off the formula

Urea from the Ghorasal plant. Predict the mass of three moles before you read the graph.

Preview6m

Which bag carries more nitrogen

Choose between urea and ammonium nitrate, then identify the element share and compound whole.

From percentages to a molecular formula

Turn composition into the simplest atom ratio, then use Mr to reveal the molecular multiplier.

Formulae hidden inside measurements

Recover element amounts from combustion products and water of crystallisation from mass loss.

Nothing is created, nothing is lost

Count the atoms before and after a reaction, and see why a formula may never be changed.

Keep the ions that actually react

Make a precipitate, remove spectator ions and prove that atoms and total charge both balance.

The reagent that stops the reaction

Two moles of nitrogen and five of hydrogen. Predict which one is left over.

Why a plant never gets all of it

Theoretical yield against the mass actually collected, set out the way the mark scheme wants.

10.

Concentration is a density of solute

Predict what happens to concentration when you add water but no extra solute.

11.

Same moles, bigger flask

C₁V₁ = C₂V₂ is conservation of moles. Predict the concentration after a fourfold dilution.

12.

Which formulae were never derived

A definition, a derived relation and a measured law read alike on a formula sheet. Only one of the three can deviate.

13.

From a burette reading to a mole ratio

Predict the titre for a 1:1 reaction, then run the four-line calculation.

14.

Equal volumes, equal numbers

Add molecules at fixed pressure and temperature, and predict what the volume does.

15.

Deducing the equation from data

Convert reacting masses and gas volumes into simplest mole ratios to deduce unknown formulae and equations.

16.

Significant figures and experimental uncertainty

Combine reading errors on balances and burettes into percentage uncertainty, and preserve significant figures.

17.

One exam question, end to end

Six marks, three parts, no options: molar mass, then maximum mass, then percentage yield.

3.1-3.7 · Chemical bonding

Ionic, covalent and metallic bonding, then the shapes that follow from electron pair repulsion, then the weaker forces between molecules. Ends with why ice floats, which no bond inside a molecule can explain.

0/12

Sodium gives, chlorine takes

Predict the charge on a sodium ion from its shell occupancy, then define the ionic bond.

Preview6m 2.

A salt crystal has no molecules

Sea salt from the coastal pans. Count how many neighbours each ion actually touches.

Preview6m

A shared pair, held by two nuclei

Decide what happens to the energy as two orbitals overlap, then meet the dative bond.

Why a double bond cannot rotate

Predict which overlap is stronger, end on end or side by side, then explain the difference.

When the dot structure fails

Liquid oxygen sticks to a magnet and O=O predicts the opposite. Bonding and antibonding orbitals give bond order, magnetism, and molecules that cannot exist.

Four pairs, one shape

Predict the bond angle in methane before you rotate it, then state the VSEPR rule.

A lone pair pushes harder

Ammonia and water have four pairs each. Predict why their bond angles differ.

The pair is rarely shared equally

Read the electronegativity gradient, then decide when a bond becomes polar.

Two polar bonds, no polar molecule

Carbon dioxide has polar bonds and no dipole. Predict why, then check the symmetry.

10.

The force that makes ice float

Almost every solid sinks in its own liquid. Predict what water does, then explain it.

11.

Ions in a sea of electrons

Predict what carries the current in a copper wire, then link the model to the properties.

12.

One exam question, end to end

Eight marks, five parts, no options: shape and angle, then repulsion, then the polarity of SF₆.

4.1-4.2 · States of matter

Gases first: pressure as molecular collisions, the gas laws, pV = nRT, and the assumptions a real gas breaks. Then solids: the unit cell, packing in a metal, and why a simple molecular solid melts so easily.

0/12

What a phase change actually costs

Predict the shape of a steady heating graph, then say what the flat parts mean.

Preview6m 2.

Pressure is molecules hitting a wall

A CNG cylinder reads 200 bar. Predict what makes the needle move before you heat it.

Preview6m

Halve the volume at fixed temperature

Predict the new pressure, then say what does not change about a single molecule.

Only kelvin makes the graph honest

Decide whether doubling the Celsius temperature doubles the pressure of a fixed gas.

pV = nRT, and the units it demands

Three gas laws are one equation. Predict the volume of one mole before you compute it.

What the model agrees to ignore

Five assumptions define an ideal gas. Predict which one you would drop first.

Where a real gas stops obeying

High pressure and low temperature break the model. Predict which assumption fails first.

One cell, repeated forever

Eight corner atoms, and only one atom per cell. Predict the count, then see the sharing.

Why metals pack tightly

Predict which arrangement leaves less empty space, then compare coordination numbers.

10.

Strong bonds, weak solid

Methane has four strong bonds and melts at -182 °C. Predict what actually breaks.

11.

One network, no molecules

Diamond, graphite, graphene and quartz. Melting a giant network breaks covalent bonds, which is why graphite is soft and still melts high.

12.

One exam question, end to end

Seven marks, three parts, no options: amount of gas, then mass, then the deviation from ideal behaviour.

About the creator

8bitlesson

Cambridge O Level, A Level and university courses, taught through interactive labs.

Mentora builds the sciences and mathematics as things you can move rather than videos you watch. Cambridge O Level and A Level mathematics, physics, chemistry and accounting, a primary mathematics track, and first-year university computer science. Every lesson works a real exam question end to end.