Chemistry paper 2

• What is the rate of reaction?

  How quickly a reaction happens
• How is the rate of reaction calculated?

  Change in quantity divided by time
• What can be measured to determine the rate of reaction?

  Mass of reactant used or product formed
• What does the mean rate of reaction indicate?

  Average rate over the time measured
• What happens to the solution in the hydrochloric acid and sodium thiosulfate experiment?

  The solution turns cloudy, increasing turbidity
• When do you stop the timer in the turbidity experiment?

  When the cross is no longer visible
• How does temperature affect the rate of reaction?

  Higher temperature decreases reaction time
• How can the volume of gas produced be measured in a reaction?

  Using a gas syringe connected to the vessel
• What does a graph of gas volume against time typically look like?

  A curve that starts steep and levels out
• How do you find the rate at any time on a graph?

  Draw a tangent at that point
• What effect does increasing concentration have on reaction rate?

  It increases the frequency of collisions
• How does increasing pressure affect gas reactions?

  It favors the reaction with fewer moles
• What happens when solid reactants are crushed?

  Increased surface area leads to faster reactions
• How does temperature affect particle movement?

  Particles move more quickly at higher temperatures
• What is activation energy?

  Energy needed for particles to react
• What is a catalyst's role in a reaction?

  Reduces activation energy needed
• What is a reversible reaction?

  Products can revert to reactants
• What happens at equilibrium in a closed system?

  Rates of forward and reverse reactions equal
• What does Le Chatelier's principle state?

  System adjusts to counteract changes
• What happens if pressure is increased in a reaction with more moles on the left?

  Favors the forward reaction, producing more products
• How does temperature affect endothermic and exothermic reactions?

  Higher temperature favors endothermic reactions
• What is the general formula for alkanes?

  C$n$H$2n +$$2$
• What do all alkane names end with?

  Suffix "ane"
• What is the first alkane in the series?

  Methane
• What is crude oil primarily composed of?

  Mostly hydrocarbons
• What is fractional distillation used for?

  To separate different length alkanes
• How does the boiling point of alkanes change with chain length?

  Longer alkanes have higher boiling points
• What is LPG?

  Liquid petroleum gas from short alkanes
• What is produced during complete combustion of alkanes?

  Carbon dioxide and water
• What is viscosity?

  Thickness or resistance to flow
• What are polymers made from?

  Long chains of repeating monomers
• What is the functional group of alkenes?

  C=C double bond
• How can you test for an alkene?

  Add bromine water; it turns colorless
• What happens when an alkene reacts with water?

  It forms an alcohol
• What is cracking in organic chemistry?

  Breaking longer alkanes into shorter ones
• What temperature is required for catalytic cracking?

  About 550°C
• What is produced when butane is cracked?

  Ethane and an alkene
• What is an alcohol?

  An organic compound with an O functional group
• What is produced during the complete combustion of ethanol?

  Carbon dioxide and water
• What happens when an alcohol is oxidized?

  It forms a carboxylic acid