5. Question 5: a) As mentioned in the manual, we have the ratio (K/H+ ), if H+ was lower than K then the equivalent point will be achieved and it will change color. And if H+ was more than K then the solution we are titrating will be the same, the equivalent point won’t be achieved, and it will be acidic solution. And to find the value of H+ is by having the value of pH, therefore the pH has changed from 7 to 9, which is by shifting from 10-7 to 10 -8 by adding the 0.01 of the base, and it will shift again from 10 -8 to 10 -9 by adding another 0.01 of the base to the solution , the different that’s added between the two shifting are close to each other which indicates that the
The data from the first experiment concluded that pH level of 4 and pH level 7 had the most activity. Thanks to the chemistry lab the pH levels were created and data was collected. In both experiments, there were procedures that were done differently that could have had an effect on the data. The
As had doing the baseline prior to changing the pH with a drastic qualitative and quantitative data change, seeing no color change and slope in the graph was concerning. However as multiple trials were completed and results were compared to other classmates, more confidence arose in the results as the numerous trials with similar results ensured validity. If there were things that could have been done differently, more precision and caution would have been taken whilst doing the lab; for example: re-reading the lab before beginning and taking time while measuring out solutions. The experiment had a few errors due to human error as well as random ones. For example, in one trial, distilled water was gathered through the hydrogen peroxide pipetter, creating a chance of error due to the cross-contamination of solutions.
Introduction Bromothymol blue is an indicator used in titration-based experiments and transitions color as the ratio of protonation, and ultimately pH, of a given solution changes. This ratio is commonly illustrated by the Henderson-Hasselback equation (pH=pKa+log[A^-/HA]), where A^- represents the concentration of conjugate base and HA is the concentration of acid in the observed sample. The concentration of a species in solution can be determined using Beer’s Law, A=Ɛbc, where absorbance of the solution at the λ_max is equal to the product of the cuvette path length, molar coefficient, and solution concentration. Therefore, absorbance is directly correlated with concentration.
This then resulted in a change of color for the indicator. Similarly Erio-Black T is also a good substance to use for testing the water samples in this experiment because it works as an indicator and changes from red then to purple and finally to blue around the pH range of 7-11. In addition, we used a pH 10 buffer to ensure that the
-Acids ionize in a flowing solution to produce hydrogen ions. -Bases produce hydroxide ions. The acid hydrogen fluoride (HF) can be dissolve in pure water. Will the pH of the solution be greater or less than 7?
In step 4 NaOH, a strong base, was added drop by drop to NaCl, a salt of a strong acid-strong base. The addition of NaOH to NaCl resulted in the pH dramatically going up which is the opposite of what happened in step 1. The initial pH of NaCl was 4.71 and when just one drop of NaOH was added the pH went up to 5.14. After all three drops of NaOH were added to NaCl the pH was tested to be 8.21, the highest pH so far. So the NaCl most certainty did not buffer the pH changes.
Introduction On Monday, in class, we executed an experiment. The objective is to… Problem Question Before completing the experiment I have to choose a problem question. I have decided to answer the following question to solve a problem; which of the three unknown concentrations of acid is the strongest?
Compare and contrast the pH results from a strong acid and a strong base addition to water and to the buffers. Physiologically, what is an example of a buffered living system and white is it important? In the case of my experiment, I added NaOH (strong base) to the solution of deionized water (DIW), and the pH increased minimally, which was surprising as I expected a higher increase based on the fact that water is not normally a good buffer. However, when compared to adding NaOH to buffers Acetate and Phosphate, they just had one initial spike in pH: Phosphate in the beginning, then gradually increased, while Acetate slowly increased, then spiked at the endpoint.
This increases the H+ activity of the solution without increasing the concentration of OH- ions in the solution. The pH of the water becomes more acidic, when increasing the drops of HCl, the pH become lower (Murmson, 2014). On average commercial buffer had a pH of 7 because when HCl was added to a commercial buffer there was no change in the pH because the commercial buffer was a weak acid, the effect of the ph will be less. As seen in figure 1 it clearly show the buffer with a constant pH of 7 compared to the other substances used. It is also because the buffer solution was composed of
Two of the same types of plants were used, in order for the results to be reliable. One of the plants was labelled DISTILLED whereas the other was ACIDIC, so the results don’t get mixed. The DISTILLED plant was used as a controlled variable, where normal spring water was used (pH 7.3) The ACIDIC plant was the one the experiment had taken place on, this was where lemon water was used (pH 2.0) Throughout the experiment pictures were taken, so one will be able to notice the colour change on the acidic plants, as it had started to slowly die. With both plants you are able to notice that they had both started to grow flowers, but more the spring watered plant than that on the lemon juice watered one. The results of the plant growth was recorded to we would be able to notice the amount it had grown, this would be the water compared to lemon juice.
Acids are proton donors in chemical reactions which increase the number of hydrogen ions in a solution while bases are proton acceptors in reactions which reduce the number of hydrogen ions in a solution. Therefore, an acidic solution has more hydrogen ions than a basic solution; and basic solution has more hydroxide ions than an acidic solution. Acid substances taste sour. They have a pH lower than 7 and turns blue litmus paper into red. Meanwhile, bases are slippery and taste bitter.
in this one, there is pollution (oil) in the water, and after the universal indicator was inserted there was just a little slight change in color, the color was like how it was in the first bottle, but this one had pollution (oil) in it bottle with half oil, salt water, and sand on bottom… this one as shown above it is very noticeable, it is easy to see the pollution (oil) on the top the sand on the bottom and the bold blue color in the middle, indicating that the the pH level had changed the most bottle with salt water and sand.. As depicted in this picture the second bottle, a slight change occurred and it was noticeable, when sand is present bottle with salt water… it is clear to see that the water only changed a slight, after the indicator was put Second trial/after 48 hours from left to right: bottle with salt water... the color changed a slight bottle with salt water and sand...
Pigments from the red cabbage help determine the pH of a solution. The pH scale is used to measure how acidic or basic a solution is. The scale used ranges from 0-14; a pH of 7 is neutral, less than 7 would be acidic and greater than 7 would be basic [1]. A pH indicator is used as a chemical detector for hydroxide and hydrogen molecules [2]. In the experiment, the red cabbage pigment called Anthocyanin was used as a pH indicator.
Strong acids and strong bases are strong electrolytes and are assumed to ionize completely in the presence of water. Weak acids however, only ionize to a limited extend in water. Any weak or strong acids when in contact with any weak or strong alkali will start to undergo neutralization regardless of their volume. When an indicator which is present in the acid-base mixture and have experienced colour change, it indicates that the mixture is in right proportions to neutralize each other and is also known as the equivalence point.
