Can I get general formulas for solving numericals of this chapter??

• One mole is the amount of a substance that contains as many particles or entities as there are atoms in exactly 12 g (or 0.012 kg) of ¹²C.
• Following relations given below can be summarized as
  • One mole of atoms = atoms = Gram atomic mass of an element.
  • One mole of molecules = molecules = Gram molecular mass of a substance.

• The concentration of a solution can be expressed in any of the following ways: Mass per cent, mole fraction, molarity and molality.

• Molarity is the number of moles of solute in per liter of solution. Unit is moles per liter.

 

• Molality is the number of moles of solute present in 1 kg of solvent.

 

• Molecular formula shows the exact number of different types of atoms present in a molecule of a compound.
• If the mass per cent of various elements present in a compound is known, then its empirical formula can be determined.
• Where, n is a simple number and may have values 1, 2, 3….
• Following steps should be followed to determine empirical formula of the compound:
  • Step 1: Conversion of mass per cent of various elements into grams.
  • Step 2: Convert mass obtained in step 1 into number of moles.
  • Step 3: Divide the mole value obtained in step 2 by the smallest mole value (out of the mole value of various elements calculated).
  • Step 4: In case the ratios are not whole numbers, they may be converted into whole numbers by multiplying by a suitable coefficient.
  • Step 5: Write empirical formula by mentioning the numbers after writing the symbols of respective elements.'