Investigating enthalpy Change - During this investigation I will be burning a selection of different alcohol's to heat a container of water.

Authors Avatar

Michael South                                Bond Energy

Investigating enthalpy Change

During this investigation I will be burning a selection of different alcohol's to heat a container of water. I will be burning four alcohols, methanol, ethanol, propanol and butanol. The aim of the experiment is to find out how much energy is produced when these alcohols are burnt and to see if there’s a relation between how many, and how strong the bonds are between molecules in the elements burnt, and how quickly the water is heated up. To put it simply, we will see if the enthalpy would increase per extra CH added

Any form of burning is an exothermic reaction; this means that heat is given out as a result. This means that the reactants energy is higher than that of the product. Alcohols react with oxygen in the air to form water and carbon dioxide.           

       The energy is given out when new bonds are formed between the water and carbon dioxide molecules. The amount of energy produced by such exothermic reactions can be calculated by using this formula:

Delta H is the amount of enthalpy (heat energy), M is the mass of the water, 4.2 is the specific temperature capacity of water (the amount of joules required to heat water by 1°C and Delta T is the waters change in temperature.

I will need to ensure that I conduct the experiments safely. As alcohols are very dangerous and highly flammable I will wear my safety goggles at all times. I will need to keep all lose items off clothing tucked in. the lids on the alcohol’s must be kept on at all times to prevent evaporation or any spillage’s.

Join now!

Apparatus

  • Retort Stand
  • Clamp
  • Copper container
  • 25ml measuring cylinder
  • Selection of fuels, methanol, butanol, ethanol and pentanol
  • Thermometer
  • Water
  • Heat proof mat

Method

  • Collect and set up apparatus as shown in the diagram
  • Measure 20ml of water in the measuring cylinder
  • Pour into copper container
  • Place thermometer in the water and measure the starting temperature
  • Weigh fuel container, record weight for before the experiment
  • Make sure all safety precautions are in place (safety goggles, heat proof mat)
  • Ignite fuel containers wick
  • When the temperature reaches 60°C put out the flame
  • Weigh the fuel container and record ...

This is a preview of the whole essay