Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Chemistry Ch 7A
Chemistry 101
Question | Answer |
---|---|
Chemical Reactions | a process in which atoms of different elements can combine/ decompose to make new compounds,atoms can be exchanged or transferred and gain or lose electrons |
Elements are not...? | transmuted during a reaction |
Evidence of Chemical Change | heat,light, color change,gas, and formation of precipitate |
Chemical Equations are | a shorthand way of describing a reaction |
Energy Symbols | D=Heat, Hn=light, shock= mechanical, elec- electrical |
In balanced chemical equations | The # of atoms of each element in reactants = the # of atoms in products |
In writing balanced equations | you 1. Write a skeletal equation by writing the formula of each reactant and product 2. Count the number of atoms of each side of the equation(Poly ions sometimes = 1 element) 3.Pick an element to balance |
How do you pick which elements to balance first | if an element is found in only one compounds on each side, balance it first, balance metals before non-metals, if an element is free on either side of the equation balance it last |
Synthesis/Combination | A + B = AB ( Two or more reactants combine to form one product) |
Decomposition | AB = A +B ( One substance splits into two or more simpler substances) |
Single Displacement | A + BC = AC +B ( One element takes place of another element) |
Double Displacement | AB + CD = AD +CB ( Two elements in the reactants exchange places) |
Aqueous Solutions | dissolving chemicals in water reacts faster, water separates the chemicals into individual molecules or ions, free-floating particles come in contact more frequently so the reaction speeds up |
Dissociation | when ionic compounds dissolve in water the anions and cations are separated from each other |
Dissociation of Polyatomic Ions | the groups stay together as one functioning ion |
Strong electrolytes | all the electrolyte molecules or formula units are separated into ions. |
In weak electrolytes | a small percentage of the molecules are separated into ions. |
In nonelectrolytes | none of the molecules are separated into ions. |
Types of Electrolytes | Salts = Water soluble ionic compounds. Acids = Form H+1 ions and anions in water solution. Strong acid = strong electrolyte, weak acid = weak electrolyte. Bases = Water-soluble metal hydroxides. Increases the OH-1 concentration. |
precipitation reactions | If a chemical reactions between ions in aqueous medium result in insoluble salts, and the insoluble salt will come out of solution as a precipitate. |
Are all ionic compounds, salts , water soluble | no |
CO32-, S2-, PO43-, OH- are soluble with | NH4+, Li+, Na+, K+ |
Cl-, Br-, R are not soluble with | Ag+, Pb12+, Hg22+ |
SO42- | Ba2+, Pb2+, Ca2+, Sr12+ |
Molecular equations are | Equations that describe the chemicals put into water and the products formed. |
complete ionic equations are | Equations that describe the actual dissolved species in water |
net ionic equation is | An equation in which the spectator ions are removed |
Properties of Acids are | sour taste, react with active metals, are corrosive, react with carbonates, and react with bases to form ionic salts |
Properties of Bases are | A.k.a. alkali's. Taste bitter. Feel slippery. Change color of litmus and vegetable dyes. Different color than acid. Litmus = blue. React with acids to form ionic salts. And often water. Neutralization. |
neutralization reactions are | acid-base reactions, The H+1 from the acid combines with the OH-1 from the base to make water, and The cation from the base combines with the anion from the acid to make the salt. |
Gas Evolution Reactions | Reactions in which one of the products escapes as a gas are called gas evolution reactions, Some reactions directly form a gas from the exchange of ions, In other reactions, the decomposition of one of products result in a gas and water. |
Oxidation–reduction reactions are | The element that loses electrons in the reaction is oxidized. The substance that gains electrons in the reaction is reduced. Oxidation and Reduction are simultaneous. |
Combustion Reactions | Combustion reactions: Reactions in which O2 is consumed by another substance. Always release heat and/or other forms of energy. Produce one or more oxygen-containing compounds. |
Gain of Oxygen Loss of Oxygen | Oxidation Reduction |
Gain of Hydrogen Loss of Hydrogen | Reduction Oxidation |
Created by:
mada22