Course

AS Chemistry: Energetics, Redox, Equilibria and Kinetics (9701)

Name: AS Chemistry: Energetics, Redox, Equilibria and Kinetics (9701)
Price: 1999 BDT

9701 topics 5 to 8, the four questions you can ask about one reaction: does it give energy out, will it go at all, how far does it go, and how fast.

48 lessons4h 45mEnglish

What you'll learn

Fix the sign of an enthalpy change from the direction the energy moves, not from the direction the thermometer moved
Build a Hess cycle from formation or combustion data, with the arrows pointing the way the data allows
Balance a half-equation on charge as well as on atoms, and combine two of them into a redox equation
Use standard electrode potentials to judge feasibility, and explain why feasible does not mean fast
Write a Kc expression with its units, and justify a shift in the words the mark scheme rewards
Read the equivalence point, the buffer region and the right indicator off a titration curve
Deduce a rate equation from initial rate data, and get the activation energy from an Arrhenius gradient

Requirements

Topic 2, the mole: moles from a mass and from a concentration, and the ratio in a balanced equation
Topic 1, electron configuration: which electrons an atom loses, and what an ion is
Topic 3, bonding: what breaking and making a bond means, since bond energies put a price on both
Topic 4, gases: pV = nRT and the molar gas volume, used wherever a gas appears in a calculation
Comfortable with logarithms, and with a graph whose axes are ln k against 1/T
A periodic table, a data booklet and a calculator beside you

Course content

48 lessons · 4h 45m

5.1-5.2 · Chemical energetics

Enthalpy change, its sign, and the four ways 9701 asks you to find it: from a temperature rise, from a Hess cycle, from enthalpies of formation, and from bond energies. Ends on what "per mole" actually refers to.

0/11

Quicklime, water, and a hot bucket

Predict the sign of ΔH for slaking lime, then fix the sign convention for good.

Preview6m 2.

The profile that climbs and stays up

Predict where the products sit on an endothermic profile, then read Ea off the same picture.

Preview6m

A thermometer measures the surroundings

q = mcΔT, and the reason m is the mass of water and not the mass of fuel.

Dissolving can make a beaker cold

Predict whether ammonium nitrate warms or cools the water, then name the two competing steps.

Every strong acid gives the same value

Predict whether HCl and HNO₃ release different amounts of energy with NaOH.

The route never changes the total

Predict whether a two-step path releases the same energy as the direct one.

A cycle built from formation values

Work the lime kiln reaction from standard enthalpies of formation, one line at a time.

Breaking costs, making pays

Predict the sign for burning methane, then account for every bond broken and made.

Per mole, or per gram

Predict how much of the energy in a fuel reaches the wheels, then compare fuels fairly.

10.

Double the equation, double the ΔH

Predict what happens to ΔH when the equation is halved, then read the units properly.

11.

One exam question, end to end

Eight marks, three parts, no options: a Hess calculation, a calorimetry result, then why they disagree.

6.1 · Electrochemistry

Redox as electron transfer, oxidation numbers and half-equations, then the cells that put that transfer to work. Standard electrode potentials, feasibility, why a tin roof rusts, and the calculation that links charge to moles.

0/11

Oxidation happens without oxygen

Predict the ion magnesium forms, then define oxidation and reduction by electrons.

Preview6m 2.

A bookkeeping rule that always works

Predict the oxidation number of sulfur in sulfuric acid, then apply the rules in order.

Preview6m

Balance the charge, not just the atoms

Predict how many electrons manganate(VII) accepts, then build the half-equation.

What a torch battery is doing

Predict which electrode the electrons leave, then name the anode and the cathode.

Two metals, one voltmeter

Predict which metal dissolves in a zinc and copper cell, then read the EMF.

Every value measured against one electrode

Predict the sign of E° for zinc, then learn the conditions that make it standard.

Will the reaction actually go

Predict whether copper displaces silver, then use the sign of E°cell to decide.

The roof is a cell nobody built

A corrugated tin roof. Predict which reagent limits the rust, then explain galvanising.

From amperes to moles of electrons

Predict the charge delivered in half an hour, then convert it with the Faraday constant.

10.

Pushing a reaction backwards

Predict where each product appears, then set out the two half-equations.

11.

One exam question, end to end

Seven marks, three parts, no options: E°cell, the negative electrode, then a mass deposited.

7.1-7.2 · Equilibria

Dynamic equilibrium, the equilibrium constant and its units, then every stress a 9701 question can apply. Ends with acids and bases: strong against weak, the pH curve, buffer regions and the choice of indicator.

0/11

Nothing changes, and nothing has stopped

Predict whether the reactions stop when the colour stops changing.

Preview6m 2.

Kc, and the units it carries

Predict whether Kc has units, then build the expression and work them out.

Preview7m

Why a warm cola goes flat

Predict what happens to the dissolved gas when the cap comes off the bottle.

Compress it and count the molecules

Predict which side an equilibrium moves to when the volume is halved.

The one stress that changes K

Predict what warming does to an endothermic equilibrium, and to Kc itself.

A catalyst moves nothing

Predict whether a catalyst raises the yield at equilibrium, then say what it does change.

Concentrated is not the same as strong

Predict the pH of 0.100 mol dm⁻³ ethanoic acid, then separate strength from concentration.

The flat part of the curve

Predict the pH at half neutralisation, then read pKa straight off the graph.

Why phenolphthalein, and not methyl orange

Predict the pH at the equivalence point of a weak acid, then choose the indicator.

10.

Ten times weaker, one pH unit up

Predict the pH after a tenfold dilution of a strong acid, then meet Kw.

11.

One exam question, end to end

Ten marks, four parts, no options: Kc and its units, then volume and temperature explained.

8.1-8.3 · Reaction kinetics

Why a reaction goes at the speed it does: collisions, activation energy and the Boltzmann distribution. Then the measurements, the rate equation, half-life, the Arrhenius plot, and what a rate equation reveals about the mechanism.

0/11

Milk in the fridge, milk on the table

Predict what fraction of collisions actually produce a reaction.

Preview6m 2.

More crowded, more collisions

Predict whether doubling the concentration always doubles the rate.

Preview6m

Ten degrees, twice the rate

Predict why a small temperature rise has such a large effect on rate.

The barrier every collision must clear

Predict whether a strongly exothermic reaction has to be fast.

A lower route over the same hill

Predict what a catalyst does to ΔH, then read both quantities off the profile.

The equation does not give the rate

Predict the shape of a rate against concentration graph for each order.

The constant that gives first order away

Predict whether the second half-life is longer than the first.

Turning a curve into a straight line

Predict what to plot against what, then take logs one line at a time.

Activation energy from a gradient

Predict the sign of the gradient, then read Ea off the line you fit.

10.

What a rate equation reveals

Two nitrogen dioxide molecules in the equation, only one in the rate equation. Predict why.

11.

One exam question, end to end

Nine marks, five parts, no options: deduce both orders, then k and its units, then the slow step.

About the creator

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