Doc Brown's Chemistry  - Chemical Calculations

On-line Quantitative Chemistry Calculations

Online practice exam chemistry CALCULATIONS and solved problems for KS4 Science GCSE/IGCSE CHEMISTRY and basic starter chemical calculations for A level AS/A2/IB * F /H (foundation/higher) represent easier/harder UK KS4 GCSE/IGCSE/KS4 science-chemistry courses * There are 16 linked sections listed below * EMAIL query?comment e.g. spotted a silly error or request for type of GCSE calculation I don't seem to have covered?

In sections 1-16 you can study definitions of the terms used and examples of how to do chemical calculations.

Sections 2 to 6 illustrate the basic 'calculation' requirements for most UK GCSE Science students. Sections 1, and 7 to 15 cover most extra material for higher GCSE student in Science, triple award or IGCSE Chemistry.

When doing the KS4-GCSE-IGCSE multiple choice science-chemistry quizzes, if you get the answer correct, a YES comes up in the box by the choices A-D. If you get it wrong, a NO appears. However, if your first three answers are incorrect, on the 4th click, which is the answer, nothing appears! This I'm afraid is peculiar quirk, in the otherwise excellent free to use Hot Potato download software I use.

Just click on the icons for notes and examples of a particular type of calculation to revise from.

To self-test yourself for revision, click on the icon for a type in answer quiz, or for a multiple choice quiz of 5Q's selected at random from the database, and there are two larger combined quizzes for foundation (F) or higher (H) GCSE/IGCSE students.

F/H suggest general foundation/higher revising guidelines for GCSE level i.e. F+H = some easy and some hard!

Please note the Quiz feedback either relates directly to the Q [???-xx] OR it may be a typical worked example.

Links to notes and examples of types of chemical calculations

[Q database code] Quizzes available

1. What is relative atomic mass? (A_r) (see also Mass Spectrometer for advanced students) and relative isotopic mass

1.[ram] Honly or Honly

2. Calculating relative formula/molecular mass (M_r) of a compound or element molecule

2.[rfm] F+H or F+H

3. Law of Conservation of Mass and simple reacting mass calculations, BUT must study sections 5. and 6. too.

3.[com] F+H or F+H

4. Composition by percentage (%) mass of elements in a compound

4.[pbm] F+H or F+H

5. Empirical formula and formula mass of a compound from reacting masses (easy start, not using moles)

5.[emp] F+H or F+H

6. Reacting mass ratio calculations of reactants and products (NOT using moles and brief mention of actual percent % yield and theoretical yield, atom economy and formula mass determination

6.[rmc] F+H or F+H

7. Introducing moles: The connection between moles, mass and formula mass - the basis of reacting mole ratio calculations (relating reacting masses and formula mass). Also extra more advanced Q's for Advanced Chemistry Students using the Avogadro Constant and with answers provided.

7.[mam] Honly or Honly

8. Using moles to calculate empirical formula and deduce molecular formula of a compound/molecule (starting with reacting masses or % composition)

8.[efm] Honly or Honly

9. Moles and the molar volume of a gas, Avogadro's Law

9.[mvg] Honly or Honly

10. Reacting gas volume ratios, Avogadro's Law and Gay-Lussac's Law (ratio of gaseous reactants-products)

10.[rgv] Honly or Honly

11. Molarity, volumes and solution concentrations (and diagrams of apparatus)

11.[msc] Honly or Honly

12. Volumetric titration calculations e.g. acid-alkali titrations (and diagrams of apparatus). Advanced level students see also advanced acid-base titration calculations page.

12.[vct] Honly or Honly

13. Electrolysis products calculations (negative cathode and positive anode products)

13.[pec] Honly or H only

14. Other calculations e.g. % purity, % percentage & theoretical yield, volumetric titration apparatus, dilution of solutions (and diagrams of apparatus), water of crystallisation, quantity of reactants required, atom economy

15. Energy transfers in physical/chemical changes, activation energies and reaction profiles etc. (notes on a separate web page)

More enthalpy calculations explained for Advanced Level

15.[et] F+H or Honly

Advanced Enthalpy Calculations with worked out answers

16. Gas calculations involving PVT relationship and determining molecular mass of a volatile liquid are on the more advanced States of Matter - Gas Laws page.

Ideal gas law P-V-T calculations

Acid-base and other non-redox titration questions

Redox volumetric titration questions

molecular equilibrium problem solving

partition and solubility product calculations

pH-pK_a/b acid-base Q's and buffer calculations

Relative atomic mass calculations and the use of a Mass Spectrometer

More advanced GCSE Higher Quiz/AS(basic) on Ex. 1. to 13. (lots of moles!) (type in answer)

Copyright © Dr W P Brown 2000-2010 All rights reserved on the revision notes, quizzes, worksheets, x-words etc.