Question | Answer | |
What does exothermic mean? | It describes a reaction that releases energy to its surroundings. | |
What does equilibrium mean? | It's a state in which the forward and reverse paths of a change take place at the same rate. | |
What is a catalyst? | It's a subsatnce that affects the reaction rate without being used up in the reaction. | |
What is decomposition? | A reaction in which a compound breaks down into two or more simpler substances. | AB-> A+B |
What is synthesis? | A reaction in which two or more substances react to form a single substance. | A+B-> AB |
What is molar mass? | The mass of one mole of a substance. | |
what is a coefficient? | A number that appears before a formula in a chemical equation. | |
What is combustion? | A reaction in which a substance reacts rapidly with oxygen, often producing heat and light. | |
What are products? | The substances formed as the result of a chemical change. | |
What are reactants? | The substances that undergo change in a chemical reaction. | |
What is endothermic? | A chemical reaction that absorbs energy from its surroundings. | |
True or false: A chemical equation must be balenced in order to show that mass is conserved during a reaction. | True | |
Chemists use a counting unit called a _______ to measure amounts of substances because chemical reactions often involve large numbers of small particals. | Moles | |
What is a double replacement reaction? | A reaction in which two different compounds exchange positive ions to form two new compounds. | AB+CD-> AD + CB |
What is an oxidation-reduction reaction? | A reaction in which electrons are transferred fro mone reactant to another. | |
What is the process in which an element gains electrons during a chemical reaction. called? | reduction | |
What is chemical energy? | The energy stored in bonds of a substance. | |
During a chemical reaction, energy is either _______ or _______. | released or absorbed | |
What is a reaction rate? | The rate at which reactants change into products over time. | |
Generally, an increase in temperature will _________ the reaction rate. | Increase | |
How does an increase in surface area affect the exposure of reactants to one another? | An increase in surface area increases the exposer of reactants to one another. | |
Why does increasing the surface area of a reactant tend to increase the reaction rate? | The increase in exposure of reatants to one another results in more collisions involving reactant particals. With more collisions, more particals will react. | |
One way that a catalyst can lower the energy barrier of a reaction is by providing a surface on which the ___________ can come together. | Reacting particals | |
What are thw two types of Equilibria? | 1. physical
2. chemical | |
What are factors affecting chemicla equilibrium? | 1. Temperature
2. Pressure
3. Concentration | |
What happens when a physical change doesn't go to comletion? | A physical equilibrium is established between the forward and reverse changes. | |
What happens when a chemical change doesn't go into completion? | A chemical equilibrium is established between the forward and reverse reactions. | |
What is a single replacement? | A reaction in which one element takes place of another element in a coumpound. | A+BC-> B+AC |