C3 Flash Cards

Measuring Rate of Reaction To measure rate you need weight/volume & time Calculate rate from gradient (y/x) Extrapolation: extend the graph Interpolation: predict within the graph Limiting Reactant: the reactant not in excess that is all used up Reaction stops when graph goes flat

Rate of Reaction Rate of reaction is faster when there is a faster rate of successful collisions Temperature: particles move faster Pressure: particles more crowded Surface area (powder): more particles available to react Concentration: more particles in the same volume Catalyst: increase the rate and is unchanged

Reacting Masses Relative Formula Mass (Mr) Add up masses from periodic table for each atom Multiply out brackets e.g. Ca(NO3)2 means there are 6 Os Mass is conserved during a reaction Number of atoms on the left is the same as on the right Calculating Mass Work out Mr for the substance your given the mass of and the substance you want to work out the mass of. Divide the mass of the substance whose mass you are given by it’s Mr. Multiply the answer by the Mr of the substance you want.

Calculations Percentage Yield Atom Economy Actual yield_ x100 Predicted yield Want high % yield to reduce the reactants wasted & reduce cost Atom Economy Mr of desired products__ x100 sum of Mr of all products Want high atom economy to reduced unwanted products & be sustainable

Bond Energy Bond making is exothermic Bond breaking is endothermic Energy given out Bond breaking is endothermic Energy taken in If a reaction is exothermic: more energy is given out than taken in If a reaction is endothermic: more energy is taken in than given out

Energy of Fuel Using a calorimeter Calculating energy transferred Use spirit burner Heat water in copper calorimeter Measure: mass of water, mass of fuel burnt, temperature change Calculating energy transferred Energy transferred equation is given: use water numbers! Energy per gram = Energy released (J)_ mass of fuel burnt (g)

Batch or Continuous Batch: used for pharmaceutical drugs Can test regularly Can make in small amounts Drugs difficult to develop & test so that its safe to use Continuous: used for chemicals e.g. ammonia Extracting chemicals form plant sources Crush plant Boil & dissolve in suitable solvent Chromatography Match melting/boiling points to see if pure

Allotropes Made of the same element but with different structures: carbon Diamond Hard so used in cutting tools Shiny so used in jewellery No free electrons so can’t conduct electricity High melting point as has strong covalent bonds Graphite Layers so can be used as pencil lead & lubricant Has free electrons so can conduct electricity High melting point as strong intermolecular forces Fullerenes Spheres to use a drug delivery systems Nanotubes can attach catalysts to