Chemistry Education

Scientists ramp up monitoring of chemicals in people’s bodies SHARE   European scientists are joining forces to find out more about the impact of common chemicals on human health, with the aim of providing solid evidence of risk that can feed into new regulations and policies. Every day we are exposed to a multitude of chemicals from sources as diverse as cars, food, clothing, paints and smartphones. Globally, 4 million tonnes of chemicals are produced every year, but how much we know about their effects on our health varies from substance to substance. Now, 107 organisations from 26 countries have come together to form the European Human Biomonitoring Initiative (HBM4EU), with the aim of answering questions in chemical risk assessment to help policymakers protect human health. Human biomonitoring involves assessing people's exposure to chemicals by measuring the amount of natural and synthetic compounds in tissues such as hair and na...

In chemistry, yield, also referred to as reaction yield, is the amount of product obtained in a chemical reaction. The absolute yield can be given as the weight in grams or in moles (molar yield). The percentage yield (or fractional yield or relative yield), which serves to measure the effectiveness of a synthetic procedure, is calculated by dividing the amount of the obtained desired product by the theoretical yield (the unit of measure for both must be the same): The theoretical yield is the amount predicted by a stoichiometry calculation based on the number of moles of all reactants present. This calculation assumes that only one reaction occurs and that the limiting reactant reacts completely. However the actual yield is very often smaller (the percent yield is less than 100%) for several reasons: 1. Many reactions are incomplete and the reactants are not completely converted to products. If a reverse reaction occurs, the final state contains both reactants and products in a state...

1. OBJECTIVE Investigate the polarity of some compounds 2. BASIC THEORY 1) Polar compounds are compounds formed by the presence of a bond between the electrons in the elements. This happens because the bonded elements have different degrees of electronegativity. · Characteristics of polar compounds: 1. Can soluble in water and other solvents 2. Have positive pole (+) and negative pole (-), due to uneven distribution of electrons 3. Have free electron pairs (when molecular shape is known) or have different electronegativity. Example: alcohol, HCl, PCl3, H2O, N2O5. 2) Non-polar compounds are compounds formed by the presence of a bond between the electrons in the elements that make up it. This happens because the binding element has the same electronegativity value / almost the same · Characteristics of non-polar compounds: 1. Insoluble in water and other polar solvents 2. It has no positive pole (+) and negative pole (-), due to uneven distribution of electrons 3. It ha...

Stoichiometry is the basic chemical calculation that states quantitative relation of chemical formulas and chemical equations. Molar Concepts and Molar Masses In SI systems, one mole is defined as the sum of the material composed of entities (atoms, molecules, or other particles) a sum of the atoms in 12 grams Carbon-12. The value of the number of atoms is 6.022 × 1023 called the Avogadro number, NA. Empirical Formulas and Molecular Formulas Empirical formulas are the simplest integer ratios of the number of moles of each element in a compound. The molecular formula represents the true number of moles of each element in 1 mole of the compound. The molecular formula may be identical to the empirical formula or an integer multiple of the empirical formula. For example, phosphoric acid (H3PO4) has a molecular formula and an identical empirical formula. Glucose has a molecular formula C6H12O6 which is a folding of 6 times its empirical formula, CH2O. The Stoichiometric Basis of Sol...

We all are made of chemicals and everything around us is made of chemicals. Everything we hear, see, smell, taste, and touch involves chemistry and chemicals (matter). Hearing, seeing, tasting, and touching all involve intricate series of chemical reactions and interactions in our body. Many of the changes we observe in the world around are caused by chemical reactions. Chemistry is not limited to beakers and laboratories. It is all around us, and the better we know chemistry, the better we know our world. Chemistry is present in every aspect of life, and few examples are- 1. sky is blue - An object is coloured because of the light that it reflects. The white light from the sun contains all the wavelengths, but when it impacts on an object some of its wavelengths are absorbed and some reflected. The colour of the sky can be explained considering phenomena named Rayleigh scattering that consists on the scattering of light by particles much smaller than its wavelength. This effect is ...

Learning Steps with a Scientific Approach Regulation of education and culture (permendikbud) No. 81 A of 2013 attachment IV, the learning process consists of five main learning activities namely: Observing, Asking, Collecting Information / Experiments, Associating / Processing Information, And, Communicating. Observe                In the process of observing learners are expected to be able to see what the teacher presents, such as video or film related material, the teacher can also display images that are also related to the material. In addition, observations can also be done at the time of the teacher to simulate. Ask                After learners observe, then learners formulate questions on what has been displayed in the teacher, if there are already questions on learners expected with the question that will make learners...

Chemical Reaction On Battery Chemical Reaction On Battery - As a basic lesson you should reread the previous page such as the explanation of electrolyte and vent plug. Understanding the description means that you are ready to learn what is being said here. Battery at the time of discharging and recharging will happen chemical reaction. Here is the full description. - Chemical Reactions On Discharging What is meant by discharging is the use of battery (capacity) content. Chemical reactions that occur are: PbO2 + 2 H2SO4 + Pb ---> PbSO4 + 2 H2O + PbSO4 At the end of discharging, the positive plate and negative plate will become PbSO4 and the electrolyte will be H2O. - Chemical Reactions On Recharging Recharging is the battery charging process. Chemical reactions that occur are: PbSO4 + 2 H2SO4 + PbSO4 ---> PbO2 + 2 H2SO4 + Pb The end of this recharging process, the positive plate returns to PbO2 and its negative plate Pb, while the electrolyte is re-formed into H2SO4. ...