Alcohols Ib Internal Assessment Chemistry

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Alcohols Internal Assessment Hypothesis I predict that as the number of CH2 chains increase, the higher the enthalpy of combustion will be. Method Apparatus Used | Uncertainty | Used for | Kept constant or replaced | Measuring Cylinder | +/- 0.5 cm3 | Measuring the volume of water | Replaced after each use | 330cm3 Can | N/A | Holding the water during heating | Replaced, but surface area exposed to flame is kept constant | Thermometer | +/- 0.5 °C | Measuring the temperature of water during heating | Replaced after each use | Electronic Balance | +/- 0.01g | Weighing the alcohols before and after heating | Reset after each use, but unit is kept constant. | Clamp and Stand | N/A | Holding the can and the thermometer in place | Kept constant | The distance from the base of the can to the wick was kept constant at 5cm by using a ruler, and the wick’s direction is kept constant by keeping it pointed to the center of the base. A volume of 100 cm3 of water is kept constant with all cans as well, and we assume that the density of water is 1g/cm3 The experiment was carried out by clamping the can to a height where the base sits 5cm from the wick, and a thermometer is clamped so that the tip reaches the approximate center of the can in full contact with the 100 cm3 of water inside it. The wick is then lit until the difference between the starting temperature and the final temperature reaches 20 °C. Raw Data Type of Alcohol (A) | Mass Before (g) (MB) | Mass After (g) (MA) | Initial Temperature (°C) (TI) | Final Temperature (°C) (TF) | Ethanol | 260.70 | 260.00 | 24 | 44 | Propanol | 178.40 | 177.75 | 24 | 44 | Buta-1-ol | 204.40 | 203.80 | 25 | 45 | Penta-1-ol | 213.03 | 212.45 | 25 | 45 | Hexa-1-ol | 160.14 | 159.67 | 25 | 45 | Processed Data Type of

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