Researching Chemistry

Researching Chemistry is the third unit in the Advanced Higher Chemistry course. It consists of four subtopics; Gravimetric analysis, Volumetric analysis, Practical skills and techniques, and Stoichiometric calculations.

Subtopics
Throughout each of the key areas the following must be considered:
 * precision
 * accuracy
 * uncertainties
 * units

Gravimetric analysis

 * Analytical determination of composition of a substance’s mass by chemically changing the substance.
 * Understanding of key techniques including ‘weighing by difference’ and ‘heating to constant mass’.

Volumetric analysis
unknown concentration. metal ion.
 * Characteristics of substances that can be used as a primary standard.
 * Preparation of a standard solution and their use in determination of a solution’s
 * Role of a control in experiments to validate techniques.
 * Use of complexometric titration in quantitative analysis of solutions containing a
 * Back titrations and associated calculations.

Practical skills and techniques

 * Preparation of standard solutions using accurate dilution technique.
 * Formation and use of calibration curves, using colorimetry to determine unknown using solutions of appropriate concentration.
 * Use of distillation, reflux, vacuum filtration, recrystallisation and use of a separating funnel in the preparation and purification of an experimental product.
 * Uses of thin-layer chromatography, melting point and mixed melting point determination in evaluating the purity of an experimental product.
 * Calculation of Rf values from relevant data and its use in following the course of a reaction.

Stoichiometric calculations

 * Calculations from balanced equations, including multi-step reactions, reactant excess, and empirical formulae from given data.
 * Calculations and explanations comparing theoretical and actual yield.