Chemistry formulas for Atoms, Molecules and Chemical Arithmetic Part II

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 = 6.02x10²³ x 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 CH₄ at 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