Rates of respiration in crest plants, which are grown in different soils with a different pH

Independent- the area where the soil sample is from.

Dependant- the amount of O2 consumption.

Materials:  For part 1 of the experiment

        Glass filter

        100 mL Erlenmeyer flask

For part 2 of the experiment

        Erlenmeyer flask 250 mL

        100 mL beaker

        10g of soil (either forest, moss, or potting soil)

        10 ml KOH 1.0 mol

        3 Cotton balls

        3 x 100 Crest seeds

        3 x 8 mL of distilled water

        3 Wooden corks

        Wool string

        Pipette 18 mL

Diagram:

Method:

Part 1

1) I did this by first collecting a sample of soil form my backyard.

2) Place the soil sample on a sheet of aluminium foil and then once all the soil is inside, you close it.

3) These aluminium packages must be placed it in the oven at 200oC for 30 minutes (so that all the water and organic matter will be desiccated.)

4) I placed 10 g of the backed soil in 8 ml of water and I stirred it gently.

5) Then I placed 10 drops of universal indicator fluid in the solution. (It was hard to see the colour, so we…read the next step)

6) With the aid of a filter I filtered out all the non-dissolved soil components, I repeated this until I had a clear solution left.

7) Once u have obtained a clear solution you can measure the pH of it.

Part 2

1) Collect materials

2) From each type of backed soil we took 10g sample and placed it in the Erlenmeyer flask.

3) Then add the 100 Crest seeds that have already been germinating for 24 hours.

4) Add 8 ml of distilled water

5) Tie the piece of woollen string around the cotton ball and then place it in KOH and remove once the cotton ball is completely satiated.

6) Place the string + cotton ball in the Erlenmeyer flask

Results:  Part 1

Table 1: The pH of the soil samples

Part 2

Table 2: The amount of O2 intake over a time period of 15 min.

(The reason why I didn’t continue recording the rate of respiration is because about 15 seconds after I hit the 15-minute mark the bubble in the treatment 3 pipette popped and directly after that the bubble popped in treatment 2 and then about a couple of seconds after that the bubble in treatment 1 also popped.)

Graph 1: The amount of O2 intake in a time span of 15 min

Table 3: The amount of Crest seeds that had sprouted after 4 days.