Buffer Solutions
Preparation and testing the properties of buffer solutions
1. To prepare two buffer solutions of pH values of 5.2 and 8.8
2. To check the pH and buffer action of the prepared buffers
3. To examine the effect of dilution of the prepared buffers on their
pH and buffering capacity
Introduction
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A buffer is a physical area or object protecting something. A chemical
"buffer" is a mixture of two compounds that protects the pH of a
solution from undergoing large changes when small amounts of acid (in
the form of hydroxonium ion [H3O+]) or base (in the form of hydroxide
ion [OH-]) are added. Buffers usually contain a weak acid and its
conjugate base or a weak base and its conjugate acid. One of the two
compounds in a buffering system acts as a proton donor, releasing H+
when pH rises, and the other as a proton acceptor, taking up H+ when
pH drops.
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Applications of buffer in chemistry include manufacture of dyes,
photographic materials, leather etc. In biochemistry the buffering
action of blood is given by the bicarbonate system, which keep the
blood pH near 7.4.
H2CO3 [IMAGE]HCO3- + H+ H2O + CO2 [IMAGE]H2CO3
[IMAGE][IMAGE][IMAGE] A number of cytoplasmic proteins can act as
buffers as they contain both acidic and basic groups. NH2- -COO- NH3+-
-COO- NH3+- -COOH
Overall negatively changed overall neutral overall positively charged
They can take up H+ the medium is acidic, and OH- when the medium is
alkaline.
In this experiment, CH3COOH(aq) and CH3COONa(aq) will make the acidic
buffer with pH<7. NH3(aq) and NH4Cl(aq) will make the alkaline buffer
with pH>7. A small amount of HCl(aq) and NaOH(aq) are added to the
buffer to observe the change in pH. The buffering capacity VS change
in concentration of buffer and buffering action of diluted buffer is
investigated.
Buffer action is the actual reaction by which a buffer system
maintains the pH upon addition of acid/base.
The capacity of the buffer is determined by the amounts of salt and
During the lab, I also learned about hypertonic solutions and hypotonic solutions. The hypertonic solution concentration of the cell is less than the outside of the cell. (Trent, 1) Hypotonic solutions have a higher concentration in it than the area surrounding it. Trent, I learned about hypertonic solutions when we placed the egg in corn syrup, which caused the egg to deform and become squished. I learned about hypotonic solutions when we placed the egg in water, which caused the egg to swell.
The null hypothesis is that there is not an optimal pH that will alter the enzymatic activity of catecholase.
the ones that contains ppt in half, then add 6M NH3 to one set of them
As a result, their habitat is being destroyed, leaving them with no place to live and to nest their young. They are also being disturbed by human activities near their habitat.
...on dioxide, within the body, affecting the pH balance of the blood. This will then affect proteins within the body, being known as enzymes, which can only function if their surrounding environment is in balance. Any alteration to this environment, will prevent the enzymes from functioning effectively.
The book I chose to read is The Filter Bubble: What the Internet is Hiding From Us by Eli Pariser. Pariser did a good job grasping my attention into this book. All the way through the text he used numerous examples from several credible outside sources to initiate these topics, ideas, problems, benefits, and solutions of the filter bubble. The text had an assortment of background stories and easily understood introductions allowing myself to understand the subject with ease. In addition Pariser avoided most of the technical jargon that only he could understand from being educated on the subject and having a background on Internet algorithms, formatting, and website administration. Pariser managed to draw me into the book using not only this easy to follow wording, but also because the subject of personalization and filtering of the internet was a recent concept to me, being one of the many people that at first thought we had almost limitless access to anything on the Internet. Since this day and age seem to revolve around technology and Internet use, the book appealed to me even more...
strong acid or base does not necessarily yield a drastic jump in pH. The acid
Nowadays, a lot of research teams are trying to develop new ways to treat cancer or to improve the efficacy of already existing treatment strategies. To do this, it is important to understand the differences between tumor tissue and healthy tissue. One of these differences concerns the pH in cancerous environment. In normal cells, intracellular pH is generally around 7,2 and thus lower than the extracellular pH of 7,4. Cancer tissue however shows a reversed pH gradient: the intracellular pH is increased (>7,4) and the extracellular pH is lower than usual (6,7-7,1). This gradient is maintained thanks to changes in the expression and activity of some particular plasma membrane ion pumps and transporters that facilitate the H+ efflux. Due to the increased intracellular pH, cell proliferation and the evasion of apoptosis is possible and the metabolic adaption is facilitated. Moreover, for efficient directed cell migration a higher intracellular pH is even obligatory. The decreased extracellular pH also offers some advantages for the development of the tumor : HCO3—-dependent buffering is limited, extracellular matrix remodeling is promoted and acid-activated proteases are stimulated which makes tumor cell invasion and dissemination easier (Webb e.a. 2011).
One of Burtynsky’s projects that made an impression on me is his Salt Pan project. The way he captures the salt pans causes the audience to perceive it as abstract. Specifically, the portrayal of the water drainage system. The diagonal and uniformed lines of the drainage system allow the audience’s eyes to follow the path. However, the path doesn’t lead anywhere new, it goes right back to where it started. Furthermore, the space that surrounds the salt pans leads the audience to focus on just the salt pan and nothing else. With the scaling and proportional of the salt pans, the pans seem so insignificant and small. However, the salt pans are the main source of life for that society, which is noted by the tire tracks. Furthermore, the dependence
The body has a buffer system that mixes of a weak acid and a weak base to resist changes in pH, it is the least efficient but it is quick. It includes buffers such as bicarbonate, phosphate, and a few proteins that help too. The respiratory system place a part too, it is a bit slower but it is more effective than the buffer system. The kidney secretion of hydrogen ions, is the most effective but is the slowest. It lowers the pH of the blood and raises pH of the urine.
An acid becomes a solution, when a hydrogen ion is released. A base becomes a solution, when a hydroxide ion is released. There are three classes of acids and bases. An acid produces H+ in a solution and a base produces OH. This is a theory called the Arrhenius definition. A man by the name of Svante Arrhenius developed this theory. Acids and bases can be defined their physical and chemical observations.
To maintain H+ in the body fluids, the input of hydrogen ions must be balanced by an equal output. On the input side only a small amount of acid capable of dissociating release H+ is taken in with food. Most hydrogen ions in the body fluids are generated internally from metabolic activities. The major source of H+ is through H2CO3 formation metabolically produced CO2. Cellular oxidation of nutrients yields energy with CO2 and H2O as end products. Catalysed by the enzyme carbonic anhydrase, CO2 and H2O from H2CO3 which then partially dissociates to liberate free hydrogen ions and HCO3-. The reaction is reversible because it can go in either direction, depending on the concentration of the substances
The effect of a change in PH on enzymes is the alteration in the ionic
The Effect of pH on the Activity of Catalase Planning Experimental Work Secondary Resources Catalase is a type of enzyme found in different types of foods such as potatoes, apples and livers. It speeds up the disintegration of hydrogen peroxide into water because of the molecule of hydrogen peroxide (H2O2) but it remains unchanged at the end of the reaction.
Bacterial cells, like plant cells, are surrounded by a cell wall. However, bacterial cell walls are made up of polysaccharide chains linked to amino acids, while plant cell walls are made up of cellulose, which contains no amino acids. Many bacteria secrete a slimy capsule around the outside of the cell wall. The capsule provides additional protection for the cell. Many of the bacteria that cause diseases in animals are surrounded by a capsule. The capsule prevents the white blood cells and antibodies from destroying the invading bacterium. Inside the capsule and the cell wall is the cell membrane. In aerobic bacteria, the reactions of cellular respiration take place on fingerlike infoldings of the cell membrane. Ribosomes are scattered throughout the cytoplasm, and the DNA is generally found in the center of the cell. Many bacilli and spirilla have flagella, which are used for locomotion in water. A few types of bacteria that lack flagella move by gliding on a surface. However, the mechanism of this gliding motion is unknown. Most bacteria are aerobic, they require free oxygen to carry on cellular respiration. Some bacteria, called facultatibe anaerobes can live in either the presence or absence of free oxygen. They obtain energy either by aerobic respiration when oxygen is present or by fermentation when oxygen is absent. Still other bacteria cannot live in the presence of oxygen. These are called obligate anaerobes. Such bacteria obtain energy only fermentation. Through fermentation, different groups of bacteria produce a wide variety of organic compounds. Besides ethyl alcohol and lactic acid, bacterial fermentation can produce acetic acid, acetone, butyl alcohol, glycol, butyric acid, propionic acid, and methane, the main component of natural gas. Most bacteria are heterotrophic bacteria are either saprophytes or parasites. Saprophytes feed on the remains of dead plants and animals, and ordinarily do not cause disease. They release digestive enzymes onto the organic matter. The enzymes breakdown the large food molecules into smaller molecules, which are absorbed by the bacterial cells. Parasites live on or in living organisms, and may cause disease. A few types of bacteria are Autotrophic, they can synthesize the organic nutrients they require from inorganic substances. Autotrophic bacteria are either photosynthetic or Chemosynthetic. The photosynthetic bacteria contain chlorophyll that are different from the plant chlorophyll. In bacterial photosynthesis, hydrogen is obtained by the splitting of compounds other than water.