# chemNRICH

##### Stage: 4 and 5 Challenge Level:

 stemNRICH : Science, Technology, Engineering, Mathematics enriched

Welcome to chemNRICH: the chemistry section of stemNRICH Advanced. This contains mathematical activities designed to complement and enhance the study of chemistry, particularly for students aged 16-19.

Area of chemical maths Style Question Description
Molecular masses Explore the distribution of molecular masses for various hydrocarbons.
Investigate the molecular masses in this sequence of molecules and deduce which molecule has been analysed in the mass spectrometer.
From the atomic masses recorded in a mass spectrometry analysis can you deduce the possible form of these compounds?
Dilutions Dilution Series Calculator In this interactive tool a bacterial solution is diluted in four stages. Can you work out what the final concentration will be? Practise with new questions until you understand the process.
Investigating the Dilution Series Follow on from the previous question by choosing the dilutions in each of four stages to try to match certain final targets.
Exact Dilutions Save on the washing up! Using just three beakers can you create dilutions of certain concentrations?
Logarithms and pH pH Temperature From a table of data for the dissociation constant of water at various temperatures, work out how hot water must be to have different pH values.
Mixing pH Use the pH formula to calculate the pH and concentrations of dilutions.
Extreme Dissociation Take the pH formula to its theoretical limits in these extreme calculations.
Blood Buffers In this extended question explore how blood buffers keep the pH levels balanced in the human body.
Atoms and particles See the Atoms and Particles problems on the physNRICH pages
Reaction kinetics Catalyse That Explore rates of a temperature dependent reaction
Reaction Types How can algebra be used to represent different reaction types? What does the equation tell us about the behaviour of the reaction?
Which reactions cause an increase in volume, and which a decrease?
Does each of these scenarios allow you fully to deduce the required facts about the reactants?
Diamonds Aren't Forever Investigate the ideal gas laws in the context of diamond gas.
Bonds, geometry and crystals Coordinated Crystals Practise your visualisation skills regarding 3D crystal structures.
Bond Angles Put your vectors to the test with this exploration of the geometry of tetrahedral molecules and ammonia.
Stereoisomers Which of these molecules can be rotated on to each other, and which are stereoisomers?
Enthalpy Which Salt? Work out why common salt is not NaCl2 by analysing the Born-Haber cycle.
Moles and molarity Conversion Sorter A molarity calculation has been written out and broken up into several pieces. Can you use the interactive tool to rearrange the pieces of the calculation into their logical order?
What does the empirical formula of this mixture of iron oxides tell you about its constituents?
Smoke and Daggers Give your general chemistry and knowledge of moles and concentrations a workout with this entertaining extended problem concerning the dangers of smoking.
Advanced mathematics in chemistry CSI: Chemical Scene Investigation Give your general quantitative chemistry and problem solving skills a workout in this entertaining extended investigation.
The Real Hydrogen Atom Dip your toe into the world of quantum mechanics by looking at the Schrodinger equation for hydrogen atoms.
Clear as Crystal Unearth the beautiful mathematics of symmetry whilst investigating the properties of crystal lattices.
Articles Inspect Your Gadgets Look at the tools and mathematics which underly quantitative chemistry.
Reaction Rates! Find out how rates of reactions and equations go together.