6 The rate and extent of chemical change

• Chemical reactions can occur at vastly different rates
• The reactivity of chemicals is a significant factor in how fast chemical reactions proceed
• There are many variables that can be manipulated in order to speed up or slow down chemical reactions
• Chemical reactions may also be reversible
• The effect of different variables needs to be established in order to identify how to maximise the yield of desired product
• Understanding energy changes that accompany chemical reactions is important for this process
• In industry, chemists and chemical engineers determine the effect of different variables on

  1. Reaction rate

  2. Yield of product
• Whilst there may be compromises to be made, they carry out optimisation processes to ensure that enough product is produced within a sufficient time, and in an energy-efficient way