- Messages
- 8
- Reaction score
- 9
- Points
- 13
There are some important things to know before the experiment.
-) Enthalpy Change: One of the most common question asked is about the improvements. Some of the possible improvements are use of lid to avoid heat loss through convection/evaporation. Improved insulation to minimise heat loss through conduction( applicable id beaker used instead of plastic cup), Use of more precisely graduated or accurate thermometer, balance or pipette instead of measuring cylinder to reduce percentage error. Increase the quantity of reactant to have greater rise in temperature that could be measured more accurately. Apart from improvements it is important to practically conclude whether a reaction is exothermic(rise in temp) or endothermic (fall in temp). The equation Q=mc(dT) should be in your mind. Take care of signs while recording enthalpy change.
-) Titration: Always try to add same drops of indicator in each titration, because otherwise you will see different intensity of color change that can disturb the experiment. Record the burette reading correct to 2 d.p. don't forget to mention units in your table. Two accurate titrations ,other than rough titre, within 0.1cm3 are enough.
-) Errors: The term least count is different from MAXIMUM ERROR. The maximum errors are :
Burette: 0.05cm3
pipette: 0.06cm3
measuring cylinder 50ml: 0.5cm3
balance: 0.05g
thermometer: 0.5 C '
I hope it will help you. Best of luck. Remember me in your prayers
-) Enthalpy Change: One of the most common question asked is about the improvements. Some of the possible improvements are use of lid to avoid heat loss through convection/evaporation. Improved insulation to minimise heat loss through conduction( applicable id beaker used instead of plastic cup), Use of more precisely graduated or accurate thermometer, balance or pipette instead of measuring cylinder to reduce percentage error. Increase the quantity of reactant to have greater rise in temperature that could be measured more accurately. Apart from improvements it is important to practically conclude whether a reaction is exothermic(rise in temp) or endothermic (fall in temp). The equation Q=mc(dT) should be in your mind. Take care of signs while recording enthalpy change.
-) Titration: Always try to add same drops of indicator in each titration, because otherwise you will see different intensity of color change that can disturb the experiment. Record the burette reading correct to 2 d.p. don't forget to mention units in your table. Two accurate titrations ,other than rough titre, within 0.1cm3 are enough.
-) Errors: The term least count is different from MAXIMUM ERROR. The maximum errors are :
Burette: 0.05cm3
pipette: 0.06cm3
measuring cylinder 50ml: 0.5cm3
balance: 0.05g
thermometer: 0.5 C '
I hope it will help you. Best of luck. Remember me in your prayers
