By: Shen Yichen Hu Qinxi Soon Hao Jing Terence Tim

Our Project How does pH affect seed germination? In this project, you will select chemicals that are acidic in nature (e.g. household chemicals) and determine their effect on germinating green gram seedlings. The effect of acidic solutions at different dilutions should be tried as well. Devise parameters to measure the effect of the chemicals, such as the number of days to germinate. Extrapolate your finding to the effect of acid rain on vegetation. From Notes

Hypothesis As the acidic level of the base increases, the germination rate of seeds will decrease.

Materials and Equipment 1.Red beans (1 pack) 2.Cotton wool (half a pack) 3.Dropper (x2) 4.pH Indicators (x20) 5.Petri Dishes (x5) 6.500ml beakers (x2) 7.100ml Measuring Cylinder 8.Hydrochloric Acid (1M HCl) (500ml) 9.Acetic Acid (1M CH3 COOH) (300ml) 10.Citric Acid (20%) (300ml)

What We Did Trial 1 We did some research on red beans(Azuki bean) and acids. Next we spread cotton wool in the Petri dish and used them as the base for growing the seeds. We had to use red beans instead of green ones because green beans germinate too quickly for us to observe the differences in the time of germination. We then diluted hydrochloric acid with water and watered the seeds in each Petri dish with the same amount of acids of different dilutions. We then checked for the number of days the seeds took to germinate. Trial 2 We researched on the pH level of normal fertilizers, and tested the pH level of the tap water we used to water the plant. This time we used two different acids to see whether the types of acid will affect germination. Then we did the same thing to each Petri dish just like in Trial 1.

Results for Trial 1 pH level Time of germination Petri Dish A 26.37pm 30 Mar Petri Dish B 37.03pm 30 Mar Petri Dish C 46.45am 30 Mar Contro l (D) 6 to pm 29 Mar Control pH 2

Other Observation and Research Observations Green mould like stuff start appearing on the cotton wool after a few days in the pH 2 and 3 dishes. The cotton wool in the control turned brownish The cotton wool in the pH 4 have some black spots on it Research The ideal pH level for soil is pH 6-7 because at this level, most of the nutrients and minerals are present in the soil. The pH level for normal fertilisers however, is 5-6.

Citric pH 3 Acetic pH 3 pH Level Time of germination Petri dish A pH4(citric)6pm 6 Apr Petri dish B pH3(citric)8pm 7 Apr Petri dish C pH4(acetic)7am 6 Apr Petri dish D pH3(acetic)6am 9 Apr Control (E) pH6-7(Water)7am 9 Apr

A little acid in the soil doesn’t really affect the rate of germination. However too much acid cause slow germination and even abnormal occurring (green stuff appearing). Also different acids have different effects on plants. So, our hypothesis is partially correct.

Causes Volcanoes Natural biological process Power plants Motorcars Factories Effect on forests include slow growth and causing damage to plants which in turn leave them more vulnerable to threats. They also cause mineral and nutrient loss from the soil.