Download to read offline
More Related Content
![8. changes to materials [Autosaved].pptx](https://cdn.slidesharecdn.com/ss_thumbnails/8-240422064255-f0401731-thumbnail.jpg?width=640&height=640&fit=bounds)
Similar to 8.1 Simple Chemical Reactions.pptx
8.1 Simple Chemical Reactions.pptx
- 1.
- 2.
- 3.
- 4. Chemicalandphysicalproperties The physical propertiesof a substance are features such as: • what colour it is • if it is a solid, liquid or a gas • what its boiling or melting temperature is • if it is heavy or light. For example : iron are that it is a grey, heavy solid with a melting point of 1538 °C. hydrochloric acid is that it is a colourless liquid
- 5. Chemicalandphysicalproperties The chemical propertiesof a substance are features such as: • how acidic or alkaline it is • how it reacts with water, acids or metals • how readily it reacts. For Example : 1. Some of the chemical properties of iron are that it combines with sulfur when heated to form iron sulfide 2. Iron combines with oxygen to form iron oxide or rust. One of the chemical properties of hydrochloric acid is that it is has a pH of 2
- 6. IntroductiontochemicalChange Chemical changes aredifferent from physical changes. physical change, no new substances are formed. For example, when liquid water freezes, the water has changed state but it is still the same substance after the change. chemical change, new substances are formed. For example, when iron and sulfur are heated together, they form a new substance (a compound called iron sulfide)
- 7. Example Chemical Changes Whenthe charcoal is heated and burned, a chemical change occurs. • The substances in charcoal react with oxygen in the air to form other substances. A chemical change is also called a chemical reaction. • One or more substances change into one or more new substances during a chemical reaction.
- 8. Differencebetween PhysicalandChemical Changes ● Physical ○A change in the state ○ Solid to liquid ○ Liquid to gas ○ Gas to liquid ○ Atoms/molecules of the substances do not change ● Chemical ○ Atoms/molecules broken down or combined to form new substances ○ Properties of new substances are different than properties of the substances that make them up
- 9.
- 10. ChemicalReactions ● A chemicalreaction is the process in which one or more substances are changed to one or more different substances to create new substances.
- 11. Reactantsand products ● Inchemical reactions, you start with reactants that are combined to make products. ○ The reactants are the starting substances. ○ The products are the new substances which result from the chemical reaction.
- 12. WORD Typesofchemicalequations FORMULA Venus has abeautiful name and is the second planet from the Sun Mercury is the closest planet to the Sun and the smallest one in the Solar System
- 13. Describingchemicalreactions REACTANTS PRODUCTS The substancesthat react together new substances made in the reaction
- 14. WordEquations ● Statements thatindicate the reactants and products in a chemical reaction. Ex. Iron + Sulfur iron sulfide ● This is read as: “Solid iron and Sulfur react (combine) to produce solid iron Sulfide” The reactants (the substances that react together) are the iron and the sulfur. The products are the new substances made in the reaction. In this reaction, there is only one product – iron sulfide
- 15. somechemicalreactions,asubstancebreaksaparttomakenew substances.Forexample,watercanbesplitaparttoformoxygen andhydrogen water → oxygen+hydrogen Chemicalreactions happen everywhere. They happen inside plants when they grow and when they decay. Chemical reactions happen inside your body to keep you alive, for example, when you digest food
- 16. CHEMISTRY & YOU Arethe changes that happen to a burning match chemical or physical changes? How do you know? A burning match is undergoing a chemical change. There is a transfer of heat, a production of light, and a change of color. The composition of the materials also changes during the burning process.
- 17. Burning Burning is achemical reaction. When a substance burns, the substance reacts with the oxygen in the air. Sometimes ashes are formed. The ashes contain new substances. The new substances in the ashes are oxides.
- 18. Charcoalismadeupoftheelementcarbon.Whencarbonburnsit combineswithoxygenintheairtomakethegascarbondioxide. Carbon→ oxygen +Carbondioxide When magnesium metal is burnt, a white powder is formed. This powder is magnesium oxide. A new substance has been formed from magnesium and oxygen. Magnesium and oxygen are the reactants. Magnesium oxide is the product. A chemical property of magnesium is that it burns in air to form magnesium oxide by combining with oxygen
- 19. Propertiesofreactantsand products Example whenburn magnesium. You can see that the properties of the product are different from those of the reactants
- 20. Reactionwithwater Some substances reactvery violently with water. Some substances do not react with water at all. Potassium (a metal) is very soft and can be cut with a knife. This is a physical property. Potassium is so reactive that it has to be stored under oil to prevent it reacting with the water vapour in the air. This is a chemical property. When a very small piece of potassium is placed in a large trough of water, hydrogen gas is given off. The reaction produces so much heat that the gas burns
- 21. ReactionwithAcid When magnesium isplaced in hydrochloric acid, bubbles of gas are given off. The magnesium has reacted with the hydrochloric acid and formed new substances. The gas is hydrogen, and magnesium chloride has been formed. This is a chemical property of magnesium When you see bubbles forming in a reaction, you know that a gas is being produced. But you cannot tell what type of gas it is. The diagrams show you how to test a gas to find out if it is hydrogen. Hydrogen gas burns with a squeaky pop. To carry out the test you light a splint and place it in the mouth of the test tube. When the hydrogen pops, it is reacting with oxygen, in the air, to form water.