c3 - quantitative chemistry

• atomic mass = mass number = top number of element
• M small r = relative formula mass = sum of atomic mass numbers of compounds
• how to find percentage mass of an element in a compound?

  atomic mass x number of atoms in the element

  / x100

  relative formula mass of the compound
• what is the Avogadro constant?

  6.02 x 10^23
• how to find number of moles?

  mass in g

  /

  relative formula mass (sum of mass number)
• what is the triange for mass, moles and mr?

  mole triangle

  A) 1

  B) 2

  C) 3

  
• why might there be a change of mass in results?

  an unsealed reaction vessel
• what is a limiting reactant?

  if one reactant gets completely used up in a reaction before the rest, then the reaction will stop, that reactant is the limiting one