Chemistry formulas for Atoms, Molecules and Chemical Arithmetic Part II
Gram Atomic Weight (GAW) related Chemical Formulas
· No. of Gram Atoms or Mole Atoms = Weight of an Element/GAW
· Weight of an Element in gram = No. of Gram Atoms x GAW
· No. of atoms in 1 GAW = 6.02x1023
· No. of atoms in given substance = 6.02x1023x Weight/GAW
· No. of atoms in 1 gram of an element = 6.02x1023/Atomic Weight
Gram Molecular Weight (GMW) related Chemical Formulas
· No. of Gram molecules or Mole Molecules = Weight of Substance/GMW
· Weight of Substance in gram = No. of Gram Molecules x GMW
· Avogadro’s No. = 6.02x1023 per mol
Mole Concept related Chemical Formulas
· 1 mole contains 6.02x1023 particles
· 1 mole of an atom = 1 GAW of it
· 1 mole of a compound = 1 GMW of it
· Examples, 1 mole of Na = 23 g
· 1 mole of H2O = 18 g
· 1 mole of OH- ions = 17 g
· 1 mole = 1 gram molecules
· 1 mole = 1 gram molecular weight
· 1 mole = 22.4 litres at NTP
· 1 mole = 6.02x1023 molecules
· 1 mole = 1 gram atomic weight
· 1 mole = 6.02x1023 atoms
· No. of Moles = Weight of Substance in Gram/Gram Molecular Weight
· No. of Moles = No. of Unitary Particles/Avogadro’s No.
· No. of Moles = Volume in Litres at NTP/22.4 Litres
Gram Molecular Volume related Chemical Formulas
· 1 Gram Molar Volume = 22.4 Litres
· Example, Volume of 16 gram (1 mole) of CH4at STP= 22.4 Litres
· Volume of 2 gram (1 mole) of H2 at STP = 22.4 Litres
· Weight of 11.2 litres of any Gas at STP = VD (Vapour Density) of that Gas in Gram
· Density of Gas at NTP = Molar Weight in Gram/22400 mL