Furthermore, chemical reactions involving two or more substances may form reaction products that are significantly more toxic than the starting reactants. Some chemicals produce adverse effects on all tissues of the body, but others tend to selectively injure a particular tissue or organ without affecting others.
Hands-on, scenario-based training is ideal because it provides the participants with the chance to practice activities and behaviors in a safe way.
For example, inadvertent mixing of formaldehyde a common tissue fixative and hydrogen chloride results in the generation of bis chloromethyl ether, a potent human carcinogen.
Although the vapor pressure of mercury at room temperature is only 0.
When working with these substances for the first time, it is prudent to consult with a safety professional prior to beginning work.
The basic tenets of toxicology are that no substance is entirely safe and that all chemicals result in some toxic effects if a high enough amount dose of the substance comes in contact with a living system.
Factors controlling the absorption of inhaled gases and vapors include the solubility of the gas in body fluids and the reactivity of the gas with tissues and the fluid lining the respiratory tract. The following are the most common classes of toxic substances encountered in laboratories.
Contact of chemicals with the eyes is of particular concern because the eyes are sensitive to irritants. Contact with Skin or Eyes Chemical contact with the skin is a frequent mode of injury in the laboratory.
Highly flammable and explosive substances make up another category of hazardous compounds, and the assessment of risk for these classes of chemicals is discussed in section 4.
If it is an organic acid or base, it will be absorbed in that part of the gastrointestinal tract where it is most fat soluble. The single most important factor that determines whether a substance is harmful or, conversely, safe to an individual is the relationship between the amount and concentration of the chemical reaching the target organ, and the toxic effect it produces.
Such operations should therefore be carried out in a laboratory chemical hood or in a glovebox.
The vapor pressure of a chemical increases with temperature; therefore, heating solvents or reaction mixtures increases the potential for high airborne concentrations. Acids and alkalis injure the skin and increase its permeability.
For volatile chemicals i. This relationship is unique for each chemical, although for similar types of chemicals, the dose-response relationships are often similar. This database provides information on toxicity of chemicals to aquatic life, terrestrial plants, and wildlife.
The affected organ e.As the plant has more CO2 the limiting factor caused by the lack of CO2 is reduced. This test did produce a big anomaly. The rate for a light intensity of is 5. CO2 concentration A1 Changes to the Earth’s atmosphere, oceans and rock deposition due to photosynthesis. State that (some) prokaryotes, algae and plants carry out photosynthesis.
IB Chemistry Internal Assessment: SAMPLE LAB FORMAT **The following titles and subtitles should be used for your lab report and given in this order within your lab report.
I. DESIGN (D) Purpose(ASPECT 1) Provide a focused, unambiguous research problem/question.
Include the factors being studied. Hypothesis Make a single. IB Environmental Systems and Societies SL Internal Assessment Uploaded by weather_gal An Internal Assessment for IB Environmental Systems and Societies is an student-chosen lab, where all lab design, data collection, analysis, and conclusions must be done by the student.4/4(7).
Lab work in class counts towards these hours Individual investigation (internal assessment-IA) - 10 hours for SL and HL A lab project along with a report that counts as 20% of your IB exam scores (written exam counts for the other 80%).
The Lab School of Washington Scientific Review Group The research literature exploring the development of creativity reports a wide range of factors that can both positively and negatively impact creative thinking.Download