Chem2

• What is the focus of the AQA chemistry paper 2 study material?

  The focus is on rates, organic analysis, atmospheric, and resources.
• What does the rate of reaction refer to?

  It refers to how quickly a reaction occurs.
• How is the rate of reaction mathematically defined?

  It is defined as the change in a quantity divided by time.
• What can the quantity in the rate of reaction represent?

  It can represent the mass of reactant used or the volume of gas produced.
• What does measuring the rate of reaction over time typically yield?

  It typically yields the mean rate of reaction.
• What is an example of an experiment to measure the rate of reaction?

  Reacting hydrochloric acid with sodium thiosulfate and observing the turbidity change.
• What does the term "increased turbidity" refer to in the context of the experiment?

  It refers to the solution becoming cloudy as the reaction proceeds.
• How can the rate of reaction be affected by temperature?

  Higher temperatures generally decrease the time taken for a reaction to occur.
• What is another method to measure the rate of reaction involving gas?

  Measuring the volume of gas produced using a gas syringe.
• What does a graph showing the volume of gas produced over time typically look like?

  It starts steeply and then levels out or plateaus.
• How can you find the rate of reaction at a specific time using a graph?

  By drawing a tangent at that point and calculating the change in quantity divided by time.
• What factors can increase the rate of a reaction?

  Increasing concentration, pressure, and surface area of reactants.
• Why does increasing temperature affect the rate of reaction?

  Particles move more quickly and collide more frequently with more energy.
• What role does a catalyst play in a reaction?

  A catalyst reduces the activation energy needed for a reaction.
• What is a reversible reaction?

  A reaction where products can revert back to reactants.
• What happens in a closed system at equilibrium?

  The rates of the forward and reverse reactions are equal, resulting in no overall change.
• What does Le Chatelier's principle state?

  If a system at equilibrium is subjected to a change, it will adjust to counteract that change.
• How does increasing pressure affect a reaction with more moles on the left side?

  It favors the forward reaction, increasing the amount of products.
• What happens to the position of equilibrium when the concentration of reactants is increased?

  The position of equilibrium shifts to the right, producing more products.
• How does increasing temperature affect an exothermic reaction?

  It favors the reverse reaction, which is endothermic.
• What is the general formula for alkanes?

  The general formula is $C_nH_{2n+2}$.
• What do all alkane names end with?

  All alkane names end with "ane".
• What is the name of the alkane with one carbon atom?

  Methane.
• What is the name of the alkane with two carbon atoms?

  Ethane.
• What is the name of the alkane with three carbon atoms?

  Propane.
• What is the name of the alkane with four carbon atoms?

  Butane.
• What is the name of the alkane with five carbon atoms?

  Pentane.
• What is the name of the alkane with six carbon atoms?

  Hexane.
• What is the process used to separate different length alkanes from crude oil?

  Fractional distillation.
• How does fractional distillation work?

  It heats crude oil to evaporate it, allowing different alkanes to condense at different heights in a column.
• Why do longer alkanes have higher boiling points?

  They have stronger intermolecular forces that require more energy to overcome.
• What is LPG and what does it contain?

  LPG is liquid petroleum gas, containing a range of short-chain alkanes up to four carbons long.
• What is petrol used for and where does it condense in the fractional distillation column?

  Petrol is used in cars and condenses just below LPG in the column.
• What is kerosene used for?

  Kerosene is used for jet fuel.
• What is diesel oil used for?

  Diesel oil is used in cars and lorries.
• What is heavy fuel oil used for?

  Heavy fuel oil is used in large ships.
• What is produced during the complete combustion of alkanes?

  Carbon dioxide and water are produced.
• How does the viscosity of longer fractions compare to shorter fractions?

  Longer fractions are more viscous, meaning they are thicker and gloopy.
• What are some uses of different fractions of crude oil?

  They can be used to make solvents, lubricants, detergents, and polymers.
• What is the difference between alkenes and alkanes?

  Alkenes have a carbon-carbon double bond, while alkanes have only single bonds.