Contributions

Eleanor Loh (9)	ü Investigation -Preparation of materials and apparatus -Recording of data
	ü Report -Background • Readings, experiences and observations that form the rationale of our investigation -Procedure • Identification of dependent, independent and controlled variables in our investigation -Data Presentation and Analysis • Organization and presentation of our data • Highlighting observable trends and relationships from our data -Personal Reflection and Contributions • Personal reflection
Fu Yixuan (11)	ü Investigation -Preparation of materials and apparatus
	ü Report -Materials • Listing materials needed to carry out the investigation -Discussion and Conclusion • Explanation on how the results will contribute to a better tomorrow • Recommendations for future research -References and Acknowledgement • References • Acknowledgement -Personal Reflection and Contributions. • Personal reflection
Jia Jixuan (14)	ü Investigation -Preparation of materials and apparatus
	ü Report -Research Question • Rephrasing of research question -Procedure • Recording down steps required to complete the investigation • Description of the location, environment, and time of the investigation • Stating how controlled variables are managed; • Description of experimental setup • Description of data collection procedure • Listing of precautions -Data Presentation and Analysis. • Organization and presentation of our data • Report on the findings of the investigation • Highlights and explainations for observable trends and relationships from the data • Identification of factors that may have affected the outcomes of our research -Personal Reflection and Contributions • Personal reflection • Tabulating the Contribution Chart

Factors Affecting the Results

4 plants are placed in the control setup, overcrowding might take place and hence, causes the plants to compete against each other for sunlight and nutrients in the solution. Eventually, this would affect the growth of the plants and hence, causing the final state of the plants appeared to be less okay -as holes are observed on the leaves of these plants- than the plant growing in the distilled water (pH value 5.8).

Highlight and Explanation of Trends and Relationships from the Data Collected

The root system of the plants growing in extremely acid or alkalic environment have turned red. However, only those plants growing in the alkalic environment have their leaves shrunk, the size of the leaves of plants living in acidic environment remained the same.

The water hyacinth placed in a slightly acid environment (Distilled water, pH 5.8) had grown better than the water hyacinths in the control setup (Tap water, pH 7.0). It was observed that the plant in distilled water appeared to be healthier than the plants in the control setup as its leaves were whole while holes were observed on the leaves of the plants in the control setup.

Findings From Investigation

3 days later, changes did occurred on all plants. Firstly, the plant growing in the acidic environment wilted and its roots turned into red colour. Secondly, plants growing in liqiuids with neutral pH values thrived. However, the one growing in a slightly acidic environment/distilled water had grown better than the one growing in the control setup. Lastly, those growing in liquids with higher pH values wilted and all their leaves had shrunk. However, growth of the water hyacinth growing in the mixture of toothpaste and tap water (pH 10.2) is better than the one growing in the extremely alkalic liquid (Dilute sodium hydroxide, pH 14.0), because no changes observed from its roots while the other hyacinth’s roots turned into red colour too.

Observable Trends

Plants thrive in near neutral pH values (pH 6-7) while the rest which had grown in extremely acid or alkaline liquids wilt and die.

Result

The results collected from the experiment are shown below in the table below.

pH Values of Liquids Used

Liquids	pH value
Sodium hydroxide	14.0
Hydrochloric acid	2.1
Distilled water	5.8
Tap water	7.0
Mixture of Toothpaste and Tap Water	10.2

Results

Plant	Liquid	pH Value	Plant Appearance (Initially)	Plant Appearance (After 3 Days)
1	Dilute Hydrochloric Acid	2.1	Whole and healthy green leaves, clumps of roots and root hairs	Roots turned red and spread out. Plant wilted. Size of the leaves remained same.
2	Distilled Water	5.8	Whole and healthy green leaves, clumps of roots and root hairs	Healthy plant. Roots remained in clumps and leaves were whole and green. Size of the leaves remained same.
3	Tap Water	7.0	Whole and healthy green leaves, clumps of roots and root hairs	Somewhat healthy plant. Roots remained in clumps, but leaves had holes. Size of the leaves remained same.
4	Toothpaste Mixture	10.2	Whole and healthy green leaves, clumps of roots and root hairs	Plant wilted. Roots were in clumps, but had turned greenish-brown. Leaves had shrunk.
5	Dilute Sodium Hydroxide	14.0	Whole and healthy green leaves, clumps of roots and root hairs	Plant wilted. Leaves shrunk while stem fattened, and roots turned reddish.

Precautions Taken to Minimise Errors

• Keep the decimal points of the data recorded constant.

• Measurements and readings will be taken carefully in order to minimise human error.

• Use suitable and.appropriate statistical methods to calculate and manipulate the data. (e.g. Graph plotting / calculation of mean, median and mode of the data)

• Ensure that the environment in which the experiment set-ups are located in are exactly the same, if not similar. This is to prevent outside factors from interfering with the results of the experiment.

• Repeat the experiment several times if time permits in order to determine if the data collected from the first experiment was not a one-off happening that would not repeat itself again under the same circumstances.

• Determine the controlled, dependent and independent variables to fully understand how the data should be collected and recorded in such a way that it is clear.