Chemistry term 1

• What is dynamic equilibrium? When the rate of reaction is equal to the rate of diffusion
• In what system can dynamic equilibrium occur in?

  Closed system
• In equilibrium, is the concentration of the reactants and products the same?

  No.
• Over time what happens to a equilibrium reaction?

  The reaction becomes stable over time and the rates become equal
• When you remove energy or cool down the reaction, what side does the reaction favour?

  Exothermic reactions favor the product side, while endothermic reactions favor the reactant side.
• What is the equilibrium law?

  The equilibrium law states that at a given temperature, the ratio of the concentrations of reactants and products in a chemical reaction is constant.
• What is the equilibrium constant?

  Keq
• What does a large equilibrium constant mean?

  A large equilibrium constant indicates that the reaction strongly favors the forward reaction
• What does a small equilibrium constant mean?

  The reaction strongly favours the reverse reaction
• What is the reaction Quotient?

  The reaction quotient (Q) is a measure of the relative concentrations of reactants and products at any point during a chemical reaction.
• When writing equilibrium equations, what states are included and what are not?

  Included states: gas, and aqueous (dissolved in water).
• Why are liquids and solids not included in equilibrium equations?

  Because their concentrations do not change throughout the reaction
• Can the equilibrium constant change?

  Yes, if concentration or temperature is altered
• What does the term RICE stand for when doing equilibrium equations?

  RICE stands for Reactants, Products, Initial concentrations, Change in concentrations, and Equilibrium concentrations.
• When is water included in equilibrium equations?

  When water is in its liquid phase, it is typically not included in equilibrium equations. However, when water is in its gaseous phase (as water vapor), it is included in equilibrium equations involving gas-phase reactions.
• What happens to an equilibrium reaction when the concentration of the reactants increases?

  Shifts to the right
• In equilibrium, change in concentration is also the same as?

  change in pressure
• What happens to an equilibrium reaction if the volume of the system is changed?

  all gases will be altered
• What happens when volume is increased in an equilibrium reaction?

  the equilibrium will shift to favor the direction that produces more moles of gas
• What happens when volume is decreased in an equilibrium reaction?

  the equilibrium will shift to favor the direction that produces fewer moles of gas
• When you add head, what happens in an endothermic and exothermic reaction?

  Endothermic: forward reaction Exothermic: reverse reaction
• What is a redox reaction?

  A reaction that involves the transfer of electrons
• What is oxidation? 


  A substance that loses electrons
• What is reduction? 


  A substance that gains electrons from the substance that underwent oxidation
• What is the oxidising agent


  A substance that causes the other susbtance to undergo reduction
• What is a reducing agent

  A substance that causes the other substance to undergo oxidation
• What is an oxidation state


  It is the indication of the number of electrons an atom gained or lost to get to its present state
• What is the rule in metal displacement for redox reactions

  Pure metals will displace the cation of another metal only if it is more active than the cation metal
• How do you balance redox reactions?

  Break it down into half equations, multiply so electrons are the same across the equations, place new coefficients into original equation
• What does it mean when the reactant quotient (Q) is equal to the Keq value?

  The system is at equilibrium
• What does it mean when the reaction quotient (Q) is greater than the Keq value? What side of the reaction will it favour?


  The system is not at equilibrium as there are too many products. Therefore it will favour the reverse reaction.
• What does it mean when the reaction quotient (Q) is less than the Keq value? What side of the reaction will it favour?

  The system is not at equilibrium as there are too many reactants. It will favour the forward reaction.
• What are galvanic cells?


  A cell that uses Redox reactions to produce electrical energy
• What does the salt bridge do in a galvanic cell?

  It connects and completes the circuit. It also carries the ions of the solutions
• What is an E° value?

  A value of the voltage of the reaction compared to hydrogen
• What does a positive E° value represent? 


  The substance is more likely to receive electrons so it has a higher oxidising strength
• What does a negative E° value represent?


  A substance is more likely to donate electrons so it will have a lower oxidising strength
• In a galvanic cell, if something undergoes reductions, what electrode is it?

  Cathode
• In a galvanic cell, if a substance undergoes oxidation, what electrode is it?

  Anode
• What is a saturated solution?


  A solution in which no more solute can dissolve at a given temperature.