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Chemical Reactions
Chapter 5 pg. 144-165
Term | Definition |
---|---|
Activation Energy | What is needed to start a chemical reaction |
Arrow | you read the arrow as "yields" in a chemical equation or formula |
Characteristics of a Chemical Reaction | changes in energy or changes in properties (produce a gas, (bubbles form), color change, precipitate forms or temperature change) |
Chemical Changes | alter the chemical properties of matter; new substances with new properties are formed |
Chemical Equation | a shorter, easier way to show chemical reaction sby using symbols instead of words |
Coefficient | a number placed in front of a chemical formula in an equation. Tells how many atoms or molecules of each reactant and product take part in the reaction |
Conservation of Mass | the amount of matter involved in a chemical reaction does not change. The total mass of the reactants must equal the total mass of the products |
Controlling Rates of Reaction | concentration, temperature, surface area, catalysts, enzymes, and inhibitors |
Decomposition Reaction | a compound breaks down into simpler substances |
Endothermic Reaction | an observable change in energy that shows a chemical reaction took place; a reaction that takes heat from the solution, absorbs energy, makes it feel cooler. |
Exothermic Reaction | an observable change in energy that shows a chemical reaction took place; a reaction that releases heat; gives off energy, makes it feel warmer; most chemical reactions are this type |
Physical Changes | alter only the physical properties of matter; no new substances are formed, Can be a change in size, shape or color; change in phase ( by increasing or decreasing temperature: solid, liquid, gas) |
Precipitate | a solid that forms from solution during a chemical reaction; observable change that shows a chemical reaction that took place |
Products | the materials you have after a chemical reaction; written on the right side of the formula |
Reactants | the materials you have at the beginning of a chemical reaction; written on the left side of the formula |
Replacement Reaction | one part of a compound is displaced by an element or compound form another substance ( also called displacement reaction) |
States of Matter | solid, liquid, gas |
Subscripts | show the number of atoms of an element in a molecule or the ratio of elements in a compound. |
Synthesis Reaction | two substances combine to form a new compound (also called composition reaction) |