Dylan Mitchell Pineapple Express Dannielle Alex

Effects of Acids Strength on Soy Bean Seeds

Question What is the optimal pH for the germination of soy bean (fabaceae) seeds?

If the water is less acidic then more seeds will germinate. Hypothesis If the water is less acidic then more seeds will germinate.

Materials 3 Beakers pH paper Acetic acid Distilled water 12 petri dishes 120 soy bean seeds (Fabaceae) White tape 2 graduated cylinders 3 stirring rods Gloves Aprons Goggles

Procedure Part 1 Part One Procedure: Gather- Beakers, pH papers, acetic acid, distilled water, stirring rod Mix distilled water and acetic acid*, then test pH and record Repeat until desired pH of 4.5, 5.5, and 6.5 are acquired Save desired mixture for part 2 *Distilled water = 6.5 *Acetic Acid = 4.5 *24 mL distilled water and 0.03g of baking soda = 7 *24 mL of distilled water + 12 mL of acetic acid + 0.06g of baking soda = 5.5

Procedure Part 2 Gather all materials on list Recreate the acids from part 1 Label each petri dish Put 10 soybean seeds in each dish Add 8mL of distilled water to the three petri dishes 4A,4B,4C Add 8mL of 4.5 solutions to the three petri dishes labeled 1A,1B, 1C Add 8mL of 5.5 solutions to the three petri dishes 2A, 2B, 2C Add 8mL of 6.5 solutions to the three petri dishes 3A, 3B 3C Water as needed. Put lids on petri dish, sit and record for 7 days

# of Seeds Germinated Per Day Quantitative Data PH # of Seeds Germinated Per Day Total Average Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 (4.5) 1a (4.5) 1b (4.5) 1c (5.5) 2a (5.5) 2b (5.5) 2c (6.5) 3a 1 7 8 8.333333 (6.5) 3b 9 (6.5) 3c (7) 4a 6 (7) 4b 10 (7) 4c

Average Number of Seeds Germinated Per Day Averages Results pH Average Number of Seeds Germinated Per Day Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 4.5 5.5 6.5 0.333333 7.666667 8 8.333333 7 0.666667 7.333333 8.666667 9

Qualitative Data Smelled terrible throughout the entire lab. Looked kind of mushy. Tan color for the seeds that did not germinate, Pale yellow color with a dark brown patch for the seeds that germinated. Acid was a milky white color at the end of the lab. The hypocotyl was a white color.

Pictures!! 

Conclusion Based on our data, our hypothesis was supported. More seeds were germinated when the water was less acidic.

Problems The pH paper was expired and did not give us an accurate reading of the 5.5 pH solution. We concluded it was actually more acidic thus not germinating. In the petri dishes with 7 pH, the seeds started to, what we assumed, decay. Some acid spillage while counting the number of seeds germinated.

Questions If we had pH paper that hadn’t expired and had we gotten the correct 5.5 pH, how would the seeds have germinated for that group. How basic (pH) could we have gone until the seeds would not germinate? How much more accurate would our pH’s have been had we used an electronic pH reader rather than pH paper? Does the acidity effect different types of seeds differently? How would the seeds have been effected if we left the seeds in the light rather than in the drawer?