bio chem lab Essay

Submitted By supergoodman
Words: 716
Pages: 3

1. Since Qualitative analysis is the method that used to known elements with unknown elements, by comparing and contrasting their properties, we can use this method in everyday life.
A. When we prepare our meal at home, we try to identify sugar to salt by testing.
B. At bank, we try to identify genuine banknotes to fake ones, by comparing their physical properties like watermarks paper quality and chemical properties which shows color changes when we put under UV light, but feck one does not charge.
C. At construction area, to identify weather the concrete is strong or weaken, because of the presence of carbon dioxide we put a bore obtained from a concrete structure in to a basic solution, the phenolphthalein is pink, so carbonation is not occurred, and if the color remain colorless in neutral or acidic solution, carbonation is occurred so the concrete structure, must be repaired. 2.
A. Some areas of a banknote fluoresce because they are made of ink or fibers that are sensitive to UV light. Since this ink or fiber is not found throughout the note, only certain areas of the note fluoresce. B. The ink or fiber that fluoresces consists of atoms that absorb UV light. The absorption of energy causes the electrons within the atoms to jump from the ground state to the excited state. When they return to the ground state, the electrons release this excess energy in the form of fluorescent light, which can be detected.
C. The qualities to distinguish genuine currency from counterfeit currency are:-
I. When we see $ 5 bills, $10, $20 bills. Under sunlight by putting a bow your head the broken line of genuine bills makes straight line. Whereas the counterfeit currency once remain the same.
II. When we scamper the true ones and release them they return to their normal position, but untrue ones does not.
III. When we rub the true genuine currency with a white piece of paper, the ink does not remain on the white piece of paper whereas when we rub the counterfeit currency with the white piece of paper the ink remains of the white piece of paper.
3. Carbonation occurs in concrete because the calcium bearing phases present are attacked by carbon dioxide of the air and converted to calcium carbonate. Normal carbonation results in a decrease of the porosity making the carbonated paste stronger. Carbonation is therefore an advantage in non-reinforced concrete. However, it is a disadvantage in reinforced concrete, as pH of carbonated concrete drops to about 7 that is a value below the passivation threshold of steel. Carbonation may be recognized in the field by the presence of a discolored zone in the surface of the concrete. The color may vary from light gray and difficult to recognize to strong orange and easy to recognize. Carbonation can be visualized by using phenolphthalein.

4. MRI stands for magnetic resonance imaging. It is a medical procedure that uses radio waves and…