Mole concept & volumetric analysis

Avogadro's number/ Avogadro's constant
1. 6.02 x 10^23
2. 1 mol of substance contains 6.92 x 10^23 particles
3. no. of atoms = no. of moles x Avogadro's no.
Relative Atomic Mass & Relative Molecular Mass
1. Relative Atomic Mass
  1. Ar
  2. ratio of the mass of one atom of an element compared to 1/12 the mass of a carbon-12 atom
2. Relative Molecular Mass
  1. Mr
  2. mass of a molecule of an element of compound over 1/12 the of one carbon-12 atom
  3. Mr = sum of all Ar of all the atoms in the molecule
3. Relative Formula Mass
  1. Mr
  2. adding the no. of mols of Ar together
4. Molar Mass
  1. mass of 1 mole of atoms of the element
  2. gmol-1
  3. no. of moles = mass of substance (g) / molar mass (gmol-1)
Percentage composition of compounds
1. given as % by mass of each element in the compound
2. Ar of element x no. of atoms of element in formula / Mr of compound
Formula of a compound
1. the empirical formula
  1. types of elements present
  2. the simplest ratio of the different types of atoms in the compound
  3. element
  4. % composition or mass
  5. Ar
  6. no. of moles = divided by Ar
  7. molar ratio
  8. simplest molar ratio
2. the molecular formula
  1. shows the actual no. of atoms of each element in a molecule
  2. determined from empirical formula if the relative molecular mass (Mr) is known
  3. empirical formula = AxBy
  4. molecular formula = (AxBy)n
  5. n = relative molecular mass (Mr) / Mr from empirical formula
Concentrayion of a solution
1. concentration (gm-3) = mass of solute (g) / volume of solution (dm-3)
2. molar concentration(moldm-3) = amount of solute (mol) / volume of solution (dm-3)
3. molar concentration (moldm-3) = concnetration (gdm-3) / molar mass (gdm-3)
4. volumetric analysis
  1. methyl orange
    1. yellow - orange - red
  2. screened methyl orange
    1. green - grey - violet
  3. write a balanced equation
  4. fill out information given from question under the equation beneath the appropriate chemical
  5. work out the number of moles of one reactant
  6. using the chemical equation, work out how many moles the other reactant reacts with
  7. find whatever the question is asking for
Application of mole concept in chemical equations
1. balanced equation
  1. molar ratio by which the reactant reacts
  2. state of the reactants and products
  3. identification of the limiting reagent
  4. amount of produce obtained
2. balance the equation
3. find the no. of moles of all the reactants
  1. n = cv
  2. n = mass/ molar mass
4. take one of the reactants & calculate how much of the other reactant is required
5. termini the limiting reagent
6. solve rest of the problem

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Mole concept & volumetric analysis

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	Created by xinyi_hann over 9 years ago