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 or volume of gas
• What does increased turbidity indicate in a reaction?

  The solution becomes cloudy
• What happens to the time taken for a reaction as temperature increases?

  It takes less time
• What does a graph of gas volume against time typically show?

  A curve that levels out over time
• How can you find the rate of reaction at a specific time on a graph?

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

  Particles collide more frequently
• How does increasing temperature affect particle collisions?

  Particles move more quickly
• What is the role of a catalyst in a reaction?

  Reduces activation energy needed
• What is a reversible reaction?

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

  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
• How does temperature affect endothermic and exothermic reactions?

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

  C_nH_2n+2
• What do all alkane names end with?

  -ane
• What is the process used to separate crude oil into fractions?

  Fractional distillation
• Why do longer alkanes have higher boiling points?

  Stronger intermolecular forces require more energy
• What is LPG?

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

  Carbon dioxide and water
• What is the difference in viscosity between longer and shorter fractions?

  Longer fractions are more viscous
• What is a polymer?

  Long chain molecules made from monomers
• What is the functional group of alcohols?

  -OH group
• What happens when alcohols combust?

  Produces carbon dioxide and water
• What is formed when an alcohol is oxidized?

  A carboxylic acid
• What is the functional group of carboxylic acids?

  -COOH group
• What is addition polymerization?

  Joining monomers with double bonds
• What is condensation polymerization?

  Joining monomers with two functional groups
• What are amino acids?

  Building blocks of proteins
• What is DNA?

  Large molecule storing genetic code
• How can purity of a substance be tested?

  By measuring melting or boiling point
• What is a formulation?

  A mixture designed for a specific use
• What can be polymerized to make polypeptides?

  Amino acids
• What is the full name of DNA?

  Deoxyribonucleic acid
• What structure does DNA form?

  A double helix
• What are the monomers that make up DNA?

  Nucleotides
• What is starch made from?

  Glucose
• What type of glucose is cellulose made from?

  Beta glucose
• Why is obtaining pure substances important in chemistry?

  To ensure accurate chemical analysis