Equilibrium
12.0 Uses the concept of equilibrium and its principles to determine the macroscopic properties of closed systems in dynamic equilibrium.
12.1 Quantitatively determines the macroscopic properties of systems with the help of the concept of equilibrium.
Explains the dynamic equilibrium using the reversible reactions in closed systems.
States macroscopic properties of a system remains unchanged after reaching the equilibrium.
Uses physical and chemical processes such as changes of state, equilibria in solutions, chemical systems, ionic systems, sparingly soluble systems and electrodes as examples to describe the systems in equilibrium.
States the equilibrium law.
Writes the equilibrium constants (Kc, Kp ) for the systems given.
Derives the relationship between Kp and Kc.
Explains the equilibrium point.
Describs how concentration pressure, temperature and catalysts affect the equilibrium point.
States Le Chatelier principle to a disturbed system.
Predicts the effect of Le Chatelier Principle due to small change in an equlibrium system.
Solves problems based on Kp and Kc.
Examines the effect of concentration on the equilibrium system Fe3+/ SCN-
Examines the effect of pressure on the equilibrium system NO2 /N2 O4
12.2 Quantifies properties of ionic equilibrium systems related to weak acids, weak bases, acidic salts and basic salts
Describes Arrhenius theory, Bronsted-Lowry theory and Lewis theory giving appropriate examples
Explains conjugate acids and bases.
Gives expressions for Kw, Ka and Kb.
Derives equations for Ka and Kb and the law of dilution.
Derives the relationship between Ka and Kb of conjugate acid-base pairs.
Solves problems using Kw, Ka and Kb.
Defines pH.
Calculates pH of aqueous solutions of acids and bases.
Calculates pH values of salt solutions considering hydrolysis of cations and anions.
Solves problems using titrations.
States that acid-base (neutralization) indicators are either weak acids or weak bases.
Expresses that indicators exhibit different colours for their unionized and ionized forms.
States that pH range (colour change interval) of an indicator depends on the value of dissociation constant of the indicator (KIn).
Points out that the selection of an indicator depends on its pKIn value which corresponds to the equivalence point pH of the titration or pH range in which abrupt pH change occurs.
Applies theory of indicators to choose the correct indicator for a particular titration.
Calculates the pH value of acid/ base reactions at the equivalence point.
Sketches the titration curves for different types of acid base titrations.
States that near the equivalence point an abrupt pH change occurs for a small volume of the solution added.
Discusses qualitatively the main features of the titration curve between Na2 CO3 and HCl.
Determines experimentally, the acidic/basic/neutral nature of aqueous solutions of salts by testing pH.
Titrates between Na2 CO3 and HCl using phenolphthalein and methyl orange.
12.3 Prepares buffer solutions according to the requirements
Define a buffer solution.
Investigates buffer solutions qualitatively and quantitatively.
Derives Henderson equation for monobasic and monoacidic buffer systems.
Uses Henderson equation for simple calculations.
Explains pH of a buffer system qualitatively and quantitatively.
12.4 Quantifies properties of equilibrium systems related to sparingly soluble ionic compounds (Heterogeneous ionic equilibria)
States that some ionic compounds are very soluble in water but some are less soluble.
Applies the principle of equilibrium for a sparingly soluble electrolyte.
Explains requirements for precipitation of ionic compound from the aqueous solution.
Applies common ion effect.
Identifies the cations by precipitation and subsequent solubility of the precipitate in different reagents.
Explains the solubility of the precipitate based on solubility product principle.
Divides the cations listed into five groups, based on the solubility products of the ionic compounds of the cations under different conditions.
Performs calculation based on solubility and solubility product, Ksp.
12.5 Investigates how liquid - vapour equilibrium varies in single component systems. (Phase equilibria)
Defines a phase.
Identifies pure liquid systems.
Explains liquid-vapour equilibrium on the basis of molecular motion.
Defines the saturated vapour pressure.
Defines the boiling temperature.
Explains the variation of vapour pressure of liquids with temperature.
Identifies the relationship between the vapour pressure and the boiling point.
Defines the critical point
Names the triple point of water using the phase diagram.
12.6 Investigates the variation of liquid - vapour equilibrium in binary liquid systems.
Applies the principles of equilibrium to a binary liquid system to derive Raoult law.
Defines an ideal solution.
Explains how and why non-ideal solutions deviate from Raoult law, using graphs between composition and vapour pressure.
Applies Raoult law to find liquid and vapour phase compositions at equilibrium.
States that simple distillation can be used to separate non volatile components in a volatile liquid.
Gives examples for a simple distillation and fractional distillation.
States that fractional distillation can be used to separate volatile components in a volatile liquid mixture.
12.7 Investigates the distribution of substances between two immiscible liquid systems.
Explain the partition coefficient KD.
Solves problems using KD.
Determines experimentally, the distribution coefficient of ethanoic acid between water and 2- butanol.