Required practicals🥼 🔭 Flashcards
Describe the required practical, of determining the specific heat capacity of vegetable oil 🥕🥒🛢️
Hint: beaker, add, immersion heater, foam, connect, leave, read, calculate
1) place a beaker on a balance, and press the zero button- this resets the balance to zero.
2) then add the oil to the beaker, and record the mass of the oil.
3) now place a thermometer, and an immersion heater into the oil, and read the starting temperature of the oil.
4) wrap the beaker in insulating foam, to reduce thermal energy transfers to the surroundings.
5) connect a joulemeter and a power pack to the immersion heater- the joulemeter tells us how many joules of electrical energy, pass into the immersion heater.
6) leave the set up for thirty amounts- allowing the temperature to rise up enough, so the thermometer can be accurately read.
7) then read the number of joules of energy that passes into the immersion heater, and also the final temperature of the vegetable oil.
8) now calculate the specific heat capacity of the oil, rearranging the specific heat capacity equation.
What a source of inaccuracy, of the calculated specific heat capacity of vegetable oil ?
Hint: passing
- thermal energy passing out of the beaker, into the air- this can be reduced by using an insulator with a lower thermal conductivity [meaning this insulator will poorly conduct energy when heated]
What is the sources of inaccuracy, of the calculated specific heat capacity of vegetable oil ?
Hint: submerged
- not all thermal energy from the immersion heater, passes into the oil- therefore ensure the immersion heater is fully submerged.
What’s another source of inaccuracy, of the calculated specific heat capacity of vegetable oil ? 🌡️
- incorrectly reading the thermometer- therefore, use an electronic temperature probe instead.
What is the sources of inaccuracy, of the calculated specific heat capacity of vegetable oil ? 🥣
Hint: stir
- thermal energy may not be spread through the oil- to reduce this, stir the oil.
What is the independent, variable of the specific heat capacity practical ? 🥕🥒🛢️
- independent variable= the type of liquid- [e.g- vegetable oil]
What is the dependent variable of the specific heat capacity practical ? 🥕🥒🛢️
- dependent variable= the temperature
What are the control variables of the specific heat capacity practical ? 🥕🥒🛢️
- control variables- the amount of liquid, and energy provided.
Describe the required practical, to determine the specific heat capacity of aluminium. 🔩
Hint: initial, turn on, several periodic, calculate, stop, monitor
1) measure the initial temperature of the aluminium block from the thermometer.
2) then turn on the power supply and start the stopwatch; whilst the power supply is on, the heater will heat up the block.
3) then take several periodic measurements- [eg. every 1 minute of the voltage and current from the voltmeter and ammeter]
4) calculate an average for each measurement at the end of the experiment [up to 10 minutes]
5) switch off the power supply, stop the stopwatch and leave the apparatus for a minute- though the temperature will still rise before it cools
6) monitor the thermometer, recording the highest temperature that it reaches, and calculate the temperature rise during the experiment.
Once you have done the required practical, for the specific heat capacity of aluminium, how can the specific heat capacity be calculated ? [5]
- the specific heat capacity equation is: E = m c ΔΘ
- to work out energy, use the equation: energy transferred = potential difference × current × time
- to find the mass, use a balance
- and to find the temperature change: subtract the beginning temperature of the block ➖ the highest temperature that it reaches
- rearrange the equation, to find the specific heat capacity: c
What are evaluations to determining the specific heat capacity, of an aluminium block ?
- Make sure the voltmeter and ammeter are initially set to zero, to avoid zero error
What are evaluations to determining the specific heat capacity, of an aluminium block ?
- joulemeter could be used to calculate energy directly- removing errors from the voltmeter, ammeter and the stopwatch
What are evaluations to determining the specific heat capacity, of an aluminium block ?
- to avoid parallax error, the temperature value should be read at eye level from the thermometer
What are some safety considerations to the required practical about specific heat capacity: aluminium.
- never touch the heater whilst it is on, as it could burn skin or set something on fire.
- moreover, run any burns immediately under cold running water for at least 5 minutes
