You are provided with the following apparatus
- Two beakers.
- A complete retold stand.
- Cotton wool.
- Access to water.
- Stop watch.
- A burette with a tap (50cm3).
- 100ml measuring cylinder.
Proceed as follows:
- Set the apparatus as follows:
- Support the burrete on a result as shown above
- Close the tap of the burrete and fill it with water to the brim
- Transfer the water to the 100ml measuring cylinder and record the volume of the water
Volume V1 =............ (1mk)
- Fill the burrette with water up to the 0cm3 mark. Drain this water into 100ml measuring cylinder and record its volume V2
The excess water above the zero mark is given by
V0 = V1 – V2
V0 =................. (1mk)
(This volume should be added to the final volume of the burette reading when water has been drained)
- Fill the burrete with water to the brim. Finally open the tap at once and start the stop watch simultaneously. Obtain the time, t taken for the level of water to reach X=10cm3
Volume drained = (V0+10) cm3
Refill the burette with water. Finally open the tap at once and start the stopwatch simultaneously. Obtain the time taken for the level of water to reach x = 20cm3
Volume drained = (V0+20) cm3
- Repeat the procedure for other values of the burette readings.
Record the volume drained and the corresponding time in the table below.
Burette reading Volume of water drained Time t (s) Log10 V 10 20 30 40 45 50
- Plot the graph of log10v (vertical axis) against time t. (5mks)
- Using your graph, calculate the value for b and n from the equation. (3mark)