To calculate the percentage contents in the humus in soil

The equipment used for this experiment is balance.

Calculations of the soil experiment:

Weight of crucible + soil = 25.66g

Weight of crucible alone = 15.92g

Weight of soil + water = 25.66g

Weight of soil without water = 25.17g

Work out the weight of water = 0.49g

Workout the % water = weight of water x 100

Weight of soil and water

0.49x100 = 1.9 %water = 1.9 %

25.66

Weight of evaporating dish = 60.69g

Weight of evaporating dish with soil = 114.98g

Hot plate 150

Temperature increased to 400 after 5min

Temperature after cooled weighed = 110.13g

54.29g of soil 49.

44g of soil without humus

49.44g 54.29g x 100 = 91%

TASK 2 (M4)

The equipments were set up on the benches.

The Bunsen burner plugged in the gas taps.

Tripod and crucible is on top of it and stared to heat up the soil.

Use the same sample and heated up the sample to burn off humus.

Sample left to cool down.

Burned off the humus of soil in the fume cupboard.

Evaporating dish for the soil on the hot plate.

Got the temperature for the hot plate and fume cupboard.

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Balance was used in this experiment for accuracy because the balance gives accurate readings.

TASK 3 (D4)

Accuracy was assured throughout the experiment by not leaning on the benches so it wouldn't affect the readings on the balance.

The measuring equipment was the balance, it was set up before using it, to take readings.

The experimental errors in this experiment can be when heating up the soil; the soil might have been burned.

Another error is that when the cooled basin is weighed it might be contaminated.

Weighing the soil on the balance with some samples left on the balance can give wrong results.

To improve the accuracy of the results is, when heating up soil be more careful and gentle with it not to burn the soil.

Next time when weighing the cooled basin make sure not to waste any of it by contaminating it.

Make sure the balance is clean before using it to measure the soil, so it gives accurate results. More quality balances can be used.

TITLE: CHECKING THE PH FOR UNKNOWN LIQUIDS.

AIM: to find the pH unknown liquids using pH meter and pH paper.

TASK 1 (P4)

The equipments used for this experiment is pH meter, pH paper and a buffer.

Results table

SOLUTION

pH USING pH PAPER

pH7 TO PH4 USING pH METER

pH7 TO pH4 USING PH METER pH7 TO pH10 USING pH METER

A

pH1 - pH 2

1.91

1.80

B

pH - pH 14

12.86

10.01

C

pH8 - pH9

10.35

10.30

D

pH6 - ph7

7.25

8.29

TASK 2 (M4)

The equipments were set up on the benches.

Beakers with labels on them.

pH4, pH7 and pH10 in the beakers.

The buffer was connected to the pH meter.

Calibrating the pH meter.

Measuring the solutions.

Washing the buffer every time of use.

pH paper was used to get a range of pH solutions.

Taking results down from the pH meter.

In this experiment pH meter was used to indicate the acidity of pH. The buffer was use to measure the pH solutions. And also pH paper was used to get a range of pH solutions.

TASK 3 (D4)

Accuracy was assured throughout the experiment by calibrating the pH meter before measuring the pH solutions.

The measuring equipments were set up before using them the buffer was connected to the pH meter and Ph paper was ready.

Experimental errors in the experiment can be that the buffer wasn't washed every time using it. Another error can be that incorrect labelling the pH solutions. The pH meters can not be giving accurate answers, calibration wasn't correct.

Improving the accuracy of measurements buffer is to be washed each time of use.

Labelling the solutions on the beaker and changing the solutions each time.

To get accurate answers from the pH meters replace them with better quality pH meters. Repeating the experiment can give accurate answers.

TITLE: RESISTANCE OF A WIRE

AIM: To find out how resistance affect the wire as the length of the wire increases.

TASK 1 (P4)

The equipments used in this experiment are power pack multimeter and ruler.

Table

MEASURMENTS

( CM)

AMPERE

(A)

VOLTS

(V)

RESISTANCE

( )

10

0.61

0.08

0.13

20

0.58

0.19

0.33

30

0.58

0.28

0.48

40

0.61

0.40

0.66

50

0.61

0.50

0.82

60

0.58

0.58

1

70

0.57

0.67

1.12

80

0.57

0.75

1.32

90

0.59

6.90

1.53

TASK 2 (M4)

Equipment was on the benches.

Power pack plugged to the socket.

Multimeters plugged to the power pack.

Amps on 10A

Volt on 20V

Wires connected to the ruler and to the power pack.

Other end of the wires connected to the multimeters.

See the resistance of the wire.

Take results down.

In this experiment power pack was used to get flow of electricity coming through. The multimeters were used to measure the current (amps) and measure the voltage (volts). Meter ruler was used to measure the resistance length of wire.

TASK 3 (D4)

Accuracy was assured throughout the experiment using the correct amps and volts on the multimeter getting the correct resistance on the wire.

The measuring equipment was set up before using it, the power pack was connected to the multimeters. And the ruler was connected to them with wires to complete circuit.

The experimental errors in this experiment can be that the multimeters weren't accurate. Another error can be the wires, depending on the wires it gives different resistance. It can be also that the wires are not straight.

To improve the accuracy of the experiment is that , using more sensitive and accurate multimeters.

Get a wires and another one compare the results.

To have a straighter wire as possible, placing it yourself to get better results.

More time for the experiment and to repeat it 2 times.

TITLE: SAMPLE OF THE GROWING CULTURE EVERY 15 MINTUES FOR AN HOUR.

AIM: To see if the culture is growing within an hour as checking it every 15 minutes for an hour.

TASK 1(P4)

The equipments used for this experiment is microscope, haemocytometer and a pippetor.

RESULTS TABLE

NUMBER OF SQUARES

TIME

NUMBER OF HOW MANY MICRO-ORGANIMS

16

15

100000

16

30

22500

16

45

320000

16

60

430000

Calculations cells/ml

1) 10 x 40 x 4000 = 100000

16

2) 10 x 90 x 4000 = 22500

16

3) 10 x 128 x 4000 = 320000

16

4) 10 x 172 x 4000 = 430000

16

TASK 2(M4)

The equipment was set up on benches.

Microscope plugged in to the socket.

Haemocytometer on the stage of the microscope.

Looking for the squares on the haemocytometer.

Finding the squares.

Use the pippetor to get 0.1ml to 100micro litres.

Mix the culture in the water bath.

Having some culture with the pippetor,

Releasing the pippetor and pushing it down.

0.9ml of water for dilution.

Turning the top of the pippetor to 900 micro litres to get the dilution.

Turning the top of the pippetor back down to 100 micro litres.

Moving the haemocytometer from the stage of the microscope.

Applying the dilution on the haemocytometer with the cover slip on it.

Putting the haemocytometer back to the microscope.

Taking down results.

In this experiment microscope was used microscope to count the growing culture. Haemocytometer was used to count how many micro-organism cells in square. It is a microscope slide that has squares and only seen under microscope. Pippetor was used to take small amount of culture and water with accurate readings.

TASK 3 (D4)

Accuracy was assured throughout the experiment by using the correct amount of the culture and water with the pippetor. The squares were found in the haemocytometer, before applying the dilution on to the haemocytometer.

The measuring equipment was set up before using it the microscope was plugged in to the socket. The haemocytometer was on the stage of the microscope. The pippetor was measured accurate for the yeast and water.

The experimental errors can be for this experiment that, the squares on the haemocytometer was not found before applying the dilution. The culture might have been added more then 0.9ml. Micro-organisms might not be counted correct. The haemocytometer might not be clean. It can be that not waited for 15 minutes or more than 15 minuets waited.