PPT-Chemical Equations Laws The Law of Conservation of Mass

In a chemical reaction the total mass of everything at the end of the reaction is the same as the total mass at the beginning The Law of Constant Composition However you make a compound it always contains the same elements in the same proportions by mass. Law of Conservation of Mass. The law of conservation of mass states that in any given chemical reaction, the total mass of the reactants equals the total mass of the products.. Chemical equations obey the law of conservation of mass. They show that all the atoms in the reactants are still present in the products.. What happens in a Chemical Reaction?. Chemical . bonds. in the reactants are . broken. , then atoms are . rearranged. to form new substances (. products. ). . The amount of . matter. does not . change. Parts of a chemical equation:. Reactants. : a substance present at the beginning of a chemical reaction. (Left side). Products. : a substance that is produced during a chemical reaction (Right Side). They tell us how much of each substance is involved in a chemical reaction. 2H. 2. + O. 2. .  2H. 2. O. 2 moles of hydrogen react with 1 mole of oxygen to make 2 moles of water. This is useful because now we can use it to work out what mass of hydrogen and oxygen we need and how much water is made. What happens in a Chemical Reaction?. Chemical . bonds. in the reactants are . broken. , then atoms are . rearranged. to form new substances (. products. ). . The amount of . matter. does not . change. The Mole. REVISION. Formulae tell you how many of each atom are in a molecule.. Different atoms have different masses.. Level 4. NEW LEARNING. Formulae and balanced equations. Formula Mass and the mole. Chemical Changes vs. Physical Changes. Physical changes are . changes in the physical appearance, state or size of a substance. .. Chemical changes are . changes in the arrangements and connections between ions and atoms, and a change in chemical properties.. THE MOLE. Mole. -The . number of C atoms in exactly 12.0 g of carbon., also a number 6.022 x 10. 23. Avogadro’s number . 6.022 x 10. 23. , the number of . particles. in a mole of . anything. More on the mole later……. The Arithmetic of Equations. Section 1. Section 1 Learning Targets. 12.1.1 – I can explain how balanced equations apply to both chemistry and everyday life.. 12.1.2 – I can interpret balanced chemical equations in terms of moles, representative particles, mass, and gas volume at STP.. In a chemical reaction the total mass of everything at the end of the reaction is the same as the total mass at the beginning.. The Law of Constant Composition. However you make a compound, it always contains the same elements in the same proportions by mass.. A. General Features of Physical and Chemical Changes. A chemical change (a . chemical reaction. ) converts . one substance into another.. Chemical reactions involve:. Breaking bonds in the . reactants . Chapter Objectives. Describe the chemical processes used in biomass production and conversion to biofuels.. Explain balancing a chemical reaction as an application of the . law of conservation of mass. What is a thermal decomposition reaction? Can you given an example?. GOOD PROGRESS:. Recall the definition of ‘conservation of mass’. Explain conservation of mass in chemical reactions. OUTSTANDING PROGRESS:. Give an example of a non-communicable disease.. What is a pathogen?. Name the four types of pathogens.. Which pathogen is the usual cause of food poisoning?. Name another disease this type of pathogen can cause in humans..