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29 Cards in this Set
- Front
- Back
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Rate of reaction |
The speed in which a reaction occurs |
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What is required for a chemical reaction to occur |
-particles of reactants must collide -colliding particles must have sufficient energy to overcome activation energy -when colliding particles have less energy than the activation energy, a non productive collision occurs |
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What is a chemical reaction dependent on? |
-magnitude of activation energy -frequencies of collisions between reactant particles -energy of commission particles relative to activation energy -orientation of colliding particles |
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Exothermic reaction |
Energy released during reaction |
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Endothermic reaction |
Energy absorbed during reaction |
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High reactants, low products |
Exothermic |
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Low reactants, high products |
Endothermic |
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Factors that affect reaction rate |
-Concentration (number of reactants) -pressure (concentration and frequency) -temperature of reaction mixture (kinetic energy) -surface area of solid reactants (more reactions) -catalyst |
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Chemical equilibrium |
When reactants and products reach constant values after a forward and back reaction occur at the same time |
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State two conditions required for a reversible reaction to come to equilibrium |
The reaction must be carried: -in a close system -at a constant temperature |
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How can the equilibrium position of a reaction be shifted? |
Altering: -concentration -pressure -temperature |
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How does altering concentration affect a system in equilibrium |
-Increasing the concentration of the reactants results results in the consumption of the added reactant, shifting the reaction to the products -decreasing the concentration results in the replacement of the removed reactants and shifts the reaction to the formation of reactants |
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How does altering pressure affect a system in equilibrium? |
-can only be applied to systems involving gas. -increasing the pressure of a system in equilibrium by decreasing the volume of the reactant vessels allows the reaction to produce less gas molecules -decreasing the pressure results in a greater number of gas molecules |
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What is a decomposition reaction |
The breaking up of a single compound into simpler substances |
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Decomposition reaction |
AB ➡ A + B |
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What is a dissociation reaction |
A reaction where ions from an ionic lattice are set free. When an ionic solid dissolves in water: -positive and negative ions in the ionic lattice are separated -an attraction between the ions and polar water molecules occurs |
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Dissociation reaction |
NaCl (s) + aq ➡ Na^+(aq) + Cl^-(aq) |
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What is an ionisation reaction |
The formation of ions where there were none before -only applied to covalent molecules (polar molecules in particular) |
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Ionisation reaction |
-covalent bond is broken in the dissolved molecule HCl(g) + H2O(l)➡H3O^+(aq) + Cl^-(aq) -covalent bond is broken in the covalent molecule NH3(aq) + H2O(l)➡NH4^+(aq) + OH(aq) |
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What is a Single displacement reaction |
Involves one element replacing the other in a compound . An element will only replace another if it is more reactive |
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Single displacement reaction |
A + BC ➡ B + AC |
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What is a double displacement reaction |
Involves reaction of two compounds to form two new compounds |
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Double displacement reaction |
AB + CD ➡ AD + CB |
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What is a precipitate |
An insoluble product formed from a reaction taking place in an aqueous solution where the ions are more attracted to each other than the water. |
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What is an acid |
Proton hydrogen donor pH below 7 |
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What is a base |
Proton hydrogen acceptors pH above 7 |
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What is an alkali |
A base that Is soluble in water |
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What is pH scale |
Describes the strength of an acidic or basic solution |
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What is an indicator |
A chemical that changes colour in the presence of an acid or an alkali |
