Question | Answer |
In a chemical reaction one or more substance (called the__) change into one o more new substances (called the __) | Reactants; Products |
Skeleton Equation | Does not indicate the relative amounts of the reactants and products |
Aqueous Solutions ex. | Usually dissolved in water; ex. Acids |
Precipitate | Solid Product that forms in an aqueous solution reaction |
Evidence of a chemical reactions ex. | Oder, Heat, Sound, Light, Gas emission, Change of color |
How can you tell if a reaction has occured? | If the chemical properties of the reactants and products are different. |
What must happen for a reaction to occur? Theory? | The particles must collide with sufficient energy; Collision Theory. |
What is Activation Energy? | The energy needed to start a reaction |
What type of reaction absorbs energy? | Endothermic Reaction |
What type of reaction releases energy? | Exothermic Reaction |
What is a substance that speeds up the reaction, but is not used up in the reaction? | Catalysts |
What is a catalyst? How is it written? | It is neither a reactant nor a product
Its formula is written above the arrow in a chemical equation. |
What does a catalyst lower? | Activation Energy |
In a reaction atoms are rearranged but what is conserved? | Mass, Energy, Charge |
What is the Law of Conservation of Mass? | - in any physical change or chemical reaction, mass is conserved; mass can neither be created nor destroyed
- Same # of atoms of each type on each side of the equation. |
What happens in a synthesis Reaction? | a chemical change in which two or more substances react to form a single new substance. |
A+B --> AB | Syntheisis |
What happens in a decomposition reaction? | A chemical change in which a single compound breaks down into two or more simpler products. |
AB --> A+B | Decomposition |
What happens in a single replacement reaction? | a chemical change in which one element replaces a second element in a compound |
AB + C -> AC+ B | single replacement |
What happens in a Double replacement reaction? | is a chemical change involving an exchange of positive ions between two compounds. |
Where do Double Replacement Reactions take place? What does it produce? | In an aqueous solution
Precipitate, Gas, or molecular compound (water) |
AB + CD -> BC +AD | Double Displacement |
What happens in a Combustion reaction? | a chemical change in which an element or compound reacts with oxygen often producing energy in the form of heat and light. |
What is often the other reactant in a combustion reaction? | Hydrocarbon |
What is a complete combustion? | a hydrocarbon reacts with oxygen gas to form carbon dioxide and water vapor |
What is incomplete combustion? | a hydrocarbon reacts with oxygen gas to form carbon monoxide and water vapor (not enough oxygen present) |
CH4 + O2 -> CO2 + 2H2O | Complete Combusion |
CH4 + O2 -> CO + 2H2O | Incomplete Combusion |
Spectator ions? | Are not involved in the chemical reaction |
Net Ionic Equation? | only shows those particles that are directly involved in the chemical change and is balanced with respect to both mass and charge |