To find out the enthalpy change of combustion by burning butanol and enthalpy.

Energy transferred

                E = m c ΔT

M represents mass of water

C represents specific heat capacity of H2O

T represents temperature

Equipment

Calorimeter

Thermometer

Measuring cylinder

Ethanol/butanol

Scales

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Set up

Method

I set up the equipment and filled my burner with the butanol and weighed it I also weighed the burner. I measured out 500cm3 of with a measuring cylinder and then I poured this into the calorimeter. I placed the thermometer in the calorimeter and then I measured the temperature of the water and then placed the burner underneath the calorimeter and lighted the burner. I used a stirrer through out to even the temperature of the H2O  When bubbles appeared in the calorimeter I put out the burner and took the temperature again. This was to make sure no H2O were lost due to boiling thereby keeping the mass of H2O constant. This was repeated again for the ethanol I made sure I used different burners so not to mix the ethanol and butanol.

Results for Ethanol

E = mcΔT

    = 500 x 4.2 x 21

    = 44100 j   = 44.1Kj

1 mol of ethanol = 46g

2.25 → 44.1Kj

∴ 46g → x

x = 44.1 x 46

          2.25

   = 901.6Kj

So  901.6 Kj Of any given amount by 1 mol = ΔHC = 901.6 Kj mol-1

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Results for butanol

E = mcΔT 

    = 500 x 4.2 x 15

    = 31500j → 31.5Kj

1 mol of butanol =74g

1.51g → 31.5Kj

∴   74g → x Kj

x = 74 x 31.5                 

          1.51            

= 1543.7Kj mol-1

So 1543.7Kj of any given amount by 1 mol = ΔHC = 1543.7Kj mol-1