Photochemical Smog

Topics: Oxygen, Ozone, Nitrogen dioxide Pages: 7 (1838 words) Published: December 8, 2012
Chemistry Assignment
Name : Lorna Ng Xin Mei
Student ID :1000620
Group Members’ Name:Sim Koshin
Chen Chui Ting
Bhindia Pooja
Title : Paper Chromatography
Photochemical Smog
Lecturer’s Name :Ms. Usha Nanthini

Table of Content
No.| Content| page|
1.| Paper Chromatography| |
| 1.1 Definition| |
| 1.2 Background| |
| 1.3 Rf Values| |
| 1.4 Principles of Paper Chromatography| |
| 1.5 Procedure of Paper Chromatography| |
| 1.6 Uses of Paper Chromatography| |
| 1.7 Application of Paper Chromatography| |
2.| Photochemical Smog| |
| 2.1 Definition| |
| 2.2 Causes of Photochemical Smog Formation| |
| 2.3 Chemistry of Photochemical Smog Photochemical Smog| | | 2.4 Effects of Photochemical Smog| |
| 2.5 Solutions| |
3.| Appendix| |
4.| References| |
| | |

Paper Chromatography
1.1 Definition
Paper chromatography is an analytical chemistry technique for separating and identifying mixtures from complex mixtures into their individual components. 1.2 Background
Chromatography is used to separate mixtures of substances into their components. All forms of chromatography work on the same principle. They all have a stationary phase (a solid, or a liquid supported on a solid) and a mobile phase (a liquid or a gas). The mobile phase flows through the stationary phase and carries the components of the mixture with it. Different components travel at different rates, depending on the differences in solubility in the solvent, and differences in the attraction to both of the phases. In paper chromatography, the stationary phase is a very uniform absorbent paper. The mobile phase is a suitable liquid solvent or mixture of solvents. 1.3 Rf Values

Some compounds in a mixture travel almost as far as the solvent does; some stay much closer to the base line. The distance travelled relative to the solvent is a constant for a particular compound as long as you keep everything else constant - the type of paper and the exact composition of the solvent, for example. The distance travelled relative to the solvent is called the Rf value. For each compound it can be worked out using the formula:

For example, if one component of a mixture travelled 9.6 cm from the base line while the solvent had travelled 12.0 cm, then the Rfvalue for that component is:

1.4 Principles of Paper Chromatography
* Capillary Action – the movement of liquid within the spaces of a porous material due to the forces of adhesion, cohesion, and surface tension. The liquid is able to move up the filter paper because its attraction to itself is stronger than the force of gravity. * Solubility – the degree to which a material (solute) dissolves into a solvent. Solutes dissolve into solvents that have similar properties. (Like dissolves like) This allows different solutes to be separated by different combinations of solvents. Separation of components depends on both their solubility in the mobile phase and their differential affinity to the mobile phase and the stationary phase. 1.5 Procedure to Carry out Filter Paper Chromatography Technique Materials required for filter paper chromatography technique: Coffee filter, plastic cups, water, rubbing alcohol, one each from several brands of black felt tip pen. But only one permanent marker is used. Rest of the entire marker should be non-permanent. Procedure for filter paper chromatography technique:

1. Take a small amount of water in a plastic cup, just enough to cover the bottom of the cup. 2. Each pen should be assigned a unique number.
3. Long strips of dimension 4 x 10 cm should be cut from the coffee filter. Filter has to cut in such a way that the grains are parallel to the shortest length of the strip. Each strip has to be folded along the 10 cm dimension so as to make a mark at the...
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