Topic 2: Managing Chemical Processes
Call Kai
Learn
Practice Test
Spaced Repetition
Match
Flashcards
Knowt Play1/70
There's no tags or description
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced | Call with Kai |
|---|
No analytics yet
Send a link to your students to track their progress
71 Terms
Q: What is a chemical reaction?
A: A process in which one or more reactants are transformed into products through the breaking and forming of chemical bonds.
Q: What is the rate of reaction?
A: The speed at which reactants are consumed or products are formed in a chemical reaction.
Q: How can the rate of reaction be measured?
A: By measuring:
The rate at which reactants disappear
The rate at which products form
Q: What does the gradient of a concentration-time graph represent?
A: The rate of reaction at that instant.
Q: What does a steep gradient indicate on a reaction graph?
A: A fast reaction occurring rapidly.
Q: What does a shallow gradient indicate on a reaction graph?
A: A slow reaction occurring gradually.
Q: What does a zero gradient indicate on a reaction graph?
A: The reaction has stopped or reached equilibrium.
Q: Why do chemical reactions involve energy changes?
A: Energy is required to break existing bonds, while energy is released when new bonds form.
Q: What is an exothermic reaction?
A: A reaction that releases more energy than it absorbs, resulting in a net release of energy.
Q: What is an endothermic reaction?
A: A reaction that absorbs more energy than it releases, resulting in a net absorption of energy.
Q: What are the axes on an energy profile diagram?
A: Y-axis = Enthalpy (energy)
X-axis = Reaction pathway/progress of reaction.
Q: What is enthalpy (H)?
A: The heat content or energy of a system at constant pressure.
Q: What does ΔH represent?
A: The change in enthalpy (energy) during a reaction.
Q: What does ΔH < 0 indicate?
A: An exothermic reaction.
Q: What does ΔH > 0 indicate?
A: An endothermic reaction.
Q: What are the three requirements for a reaction to occur according to collision theory?
A: Particles must:
Collide
Collide with correct orientation
Have sufficient energy to overcome activation energy
Q: What is a successful collision?
A: A collision that produces products and causes a chemical change.
Q: What is an unsuccessful collision?
A: A collision that does not produce products.
Q: What is activation energy (Ea)?
A: The minimum energy required for particles to react successfully.
Q: What happens if particles collide with less than the activation energy?
A: They bounce apart without reacting.
Q: What determines the rate of reaction according to collision theory?
A: The number of successful collisions per unit time.
Q: What five factors affect reaction rate?
A: Temperature, concentration, pressure, surface area, and catalysts.
Q: How does increasing temperature increase reaction rate?
A: Particles:
Move faster
Collide more often
Have more energy
Produce more successful collisions.
Q: How does increasing concentration increase reaction rate?
A: More particles per unit volume causes more collisions and more successful collisions.
Q: Why does increasing pressure increase reaction rate in gases?
A: Gas particles are closer together, causing more frequent collisions.
Q: Why does increasing surface area increase reaction rate?
A: More particles are exposed, allowing more collisions and successful collisions.
Q: What is a catalyst?
A: A substance that increases reaction rate without being consumed.
Q: What is a homogeneous catalyst?
A: A catalyst in the same state as the reactants.
Q: What is a heterogeneous catalyst?
A: A catalyst in a different state from the reactants.
Q: How do catalysts increase reaction rate?
A: They provide an alternative reaction pathway with lower activation energy.
Q: What happens to a catalyst during a reaction?
A: It remains chemically unchanged and is not consumed.
Q: What is an irreversible reaction?
A: A reaction that proceeds only in the forward direction.
Q: What is a reversible reaction?
A: A reaction where reactants form products and products can reform reactants.
Q: What is equilibrium?
A: A dynamic state where forward and reverse reaction rates are equal.
Q: What happens to concentrations at equilibrium?
A: They remain constant because forward and reverse rates are equal.
Q: Does equilibrium mean reactant and product concentrations are equal?
A: No. Concentrations remain constant but are not necessarily equal.
Q: What does equilibrium lying to the right mean?
A: Products have a greater concentration than reactants.
Q: What does equilibrium lying to the left mean?
A: Reactants have a greater concentration than products.
Q: What is Kc?
A: The ratio of product concentrations to reactant concentrations at equilibrium.
Q: What does Kc > 1 mean?
A: Products are favoured and equilibrium lies to the right.
Q: What does Kc < 1 mean?
A: Reactants are favoured and equilibrium lies to the left.
Q: When does Kc change?
A: Only when temperature changes.
Q: Do concentration changes affect Kc?
A: No. They change equilibrium position but not Kc.
Q: Do pressure changes affect Kc?
A: No. They change equilibrium position but not Kc.
Q: State Le Chatelier's Principle.
A: When a system at equilibrium is disturbed, it shifts to oppose the change and re-establish equilibrium.
Q: What happens if reactant concentration increases?
A: Equilibrium shifts right to use up reactants.
Q: What happens if reactant concentration decreases?
A: Equilibrium shifts left to replace reactants.
Q: What happens if product concentration decreases?
A: Equilibrium shifts right to make more product.
Q: What happens if pressure increases?
A: Equilibrium shifts towards the side with fewer moles of gas.
Q: What happens if pressure decreases?
A: Equilibrium shifts towards the side with more moles of gas.
Q: In equilibrium questions, how should heat be treated?
A: As a reactant or product.
Q: For an endothermic reaction, heat is considered a _____?
A: Reactant.
Q: For an exothermic reaction, heat is considered a _____?
A: Product.
Q: What happens when temperature increases?
A: Equilibrium shifts in the endothermic direction.
Q: What happens when temperature decreases?
A: Equilibrium shifts in the exothermic direction.
Q: What is a raw material?
A: An unprocessed material used to produce other substances or energy.
Q: What is a waste product?
A: An unwanted, unusable product formed during a chemical process.
Q: What is a by-product?
A: A useful secondary product formed during a chemical process.
Q: What is a flow chart?
A: A diagram showing the stages of a chemical process from raw materials to final products.
Q: What is yield?
A: The quantity of product obtained from a chemical process.
Q: What is actual yield?
A: The amount of product actually recovered.
Q: What is theoretical yield?
A: The amount predicted using stoichiometry.
Q: What is percentage yield?
A: (Actual Yield ÷ Theoretical Yield) × 100.
Q: Catalyst used in the Contact Process?
A: Vanadium pentoxide (V₂O₅).
Q: Product of the Contact Process?
A: Sulfuric acid (H₂SO₄).
Q: Catalyst used in the Haber Process?
A: Powdered iron (Fe).
Q: Product of the Haber Process?
A: Ammonia (NH₃).
Q: Why do catalysts benefit industry?
A: Faster reactions, lower operating costs, less energy use, and reduced environmental impact.
Q: Why isn't extremely high pressure always used industrially?
A: It is expensive, potentially dangerous, and may not increase yield enough to justify costs.
Q: Why are high temperatures environmentally problematic?
A: They require fossil fuel combustion, producing greenhouse gases and pollutants.
Q: Why are industrial compromise conditions used?
A: To balance reaction rate, yield, cost, safety, and environmental impact while maintaining profitability.