Gillian McAfee's Enzyme lab

Hypothesis:The lower the pH the larger the reaction would be once mixed with the chemical.

Independent Variable: pH of the solution

Dependent Variable: Reaction time

Controlled Variables: bindweed and hydrogen peroxide mixture and water

Justification of hypothesis:

My lab group chose this as our hypothesis because the lower the pH level the more acidic the liquid is. Hydrogen peroxide is also an acid so we believed that the two acids would react and an acid and a base would level out.

Materials (Your Team’s Experiment):

• Bindweed (10 grams each time you grind into paste)
• Water
• Mortar and pestle
• 3 100-liter glass or plastic beakers
• 1 mL syringe
• Hydrogen peroxide (5 mL x6)
• 1 Paper towel square (for filtration)
• Glass test tubes
• Test tube rack or holder
• Small plastic ruler
• Safety glasses
• stopwatch or phone

Procedure/ detailed steps:1)First you put 10 grams of bindweed in to the montar.

2)Then, you grind up the bindweed until it is no longer solid.

3)Add 20mm of water into the mortar filled with the ground up bindweed.

4)Mix the water and plant together for about five minutes until the substance is liquid like.

5)Place a napkin over a beaker, and use the napkin as a strain to separate the liquid and leftover waste from the bindweed solution.

6)syringe out 10mm of the bindweed solution from the the bindweed solution from the beaker into a small test tube, with a ruler attached.

7)Add 5 mL of hydrogen peroxide.

8)When the solution starts to foam, measure the height, every 5 seconds.

9)Measure the time is takes for the substance to rise to its maximum height it gets to  and how much the bubbles rise.

10)Record the data until the mixture stops rising

11)Repeat the procedure, but this time quickly add NaOH (pH 10) with the bindweed and hydrogen peroxide.

12)Repeat step eleven, but substitute for the NaOH (pH 10) with NaOH (pH 12), HCI (pH 2-3), HCI (pH 3-4), or H2O (pH 7) all at separate times all while recording the data.

Summary:For our experiment we tested different pH levels on a bindweed solution. First we made the bindweed solution and saw how much it rose by itself. Then we repeated the process, this time adding NaOH (pH 10). we recorded how fast the solution rose and when it stopped rising. We repeated this with NaOH (pH 12), HCI (pH 2-3), HCI (pH 3-4), and H2O (pH 7) and recorded the results.

Data and Results:

Data

Height-mm	Bindweed solution (control)	HCI pH 2-3	NaOh pH 10	HCI pH 3-4	NaOH pH 12	H2O pH 7 (control)
5 sec	5	0	6	1	21	5
10 sec	9	1	10	3	24	10
15 sec	11	5	15	6	26	13
20 sec	11	8	19	9	28	15
25 sec	12	9	23	11	29	16
30 sec	14	10	25	12	30	18
35 sec	14	11	27			19
40 sec	15	12	30			19
45 sec			34
50 sec			34
55 sec			36
60 mec			38
65 sec			40
70 sec

Conclusions:Our hypothesis turned out to be the complete opposite of what happened. We predicted the more acidic the liquid, the higher the pH level would be. What we found out is that the liquids mixed with bases made the solution rise faster and higher. I wonder why a solution with a pH of 10 compared with one of 12, would rise for a longer amount of time. The NaOH (pH 12) started very high, but stopped after 30 seconds. The reaction was fast and short compared to the other solution. The other solution rose slower but was more continuous. To improve our experiment we could just use an acid, base, and neutral all the same number apart from one another to compare. We could also see how adding more bindweed or hydrogen peroxide would affect how fast the liquid rises  and how long it rises.

Our controlled variables ,water and the original bindweed solution, we very similar. The water, which has a pH of 7, started at about 5 and ended at a little under 20 mm. The bindweed solution also started at 5 millimeters, but ended at around 15 millimeters. Both also ended after 40 seconds also. This helps us indicate that the bindweed solution’s pH is probably around seven maybe a little lower. The two liquids that rose the least  were both the two lowest in pH. HCI pH 2-3 rose to 12 millimeters, while the HCI pH 3-4 rose to 12 just like the other HCI.

Despite our hypothesis being completely wrong, we discovered that liquids with a lower pH, react more with thee mixture of bindweed and hydrogen peroxide.