1.02 Amount of Substance

• What is the symbol for amount of substance?

  n
• What is the unit used to measure amount of substance?

  Mole
• What does the Avogadro constant represent?

  Number of atoms per mole of the carbon-12 isotope
• How to calculate mass of 1 mole of the element?

  mass of 1 mole = RAM of element in grams
• State Avogadro's law


  Under the same temperature and pressure, one mole of any gas would occupy the same volume
• How much volume does a gas occupy, at room temperature+pressure?

  24dm^3
• Define molar gas volume


  The volume per mole of gas molecules
• Why do different gas particles occupy the same volume?

  The gas particles are very spread out, hence individual differences have no effect
• How to calculate moles when gas volume is given?

  moles (mol) = vol (dm^3)/24
• What are the ideal ways in which gases behave?

  • In continuous motion
  • No intermolecular forces experienced
  • Exert pressure when they collide with eachother or on container
  • No Ek is lost in the collisions
  • When temperature increases, Ek of gases increase
• Write down the ideal gas equation (in words+symbols including units)

  pV = nRT

  pressure (pa) x volume (m^3) = number of moles (mol) x gas constant (8.314J/mol) x temperature (k)
• 1 atmospheric pressure is equal to how many pascal?

  1 atm = 101325 Pa
• 0 degrees celsius is equal to how many kelvin?

  273 K
• What does concentration of a solution mean?


  Amount of solute dissolved in 1dm^3 of solvent
• What is a standard solution?

  A solution of known concentration
• What does the terms concentrated and dilute mean?


  concentrated - large amount of solute per dm^3 of solvent

  dilute - small amount of solute per dm^3 of solvent
• What is a species in a chemical reaction?

  Any particle that takes part in a reaction