Lecture one- Pharmacy collage first Year

Analytical Chemistry

Such as the amount of Active compounds in pharmaceutical formulations or biological samples.

There are also different methods such as separation methods for example chromatographic separation methods.

Molar mass(M) or Molecular weight(M.Wt)

Molarity(M)= (mass / M.Wt) x (1000/Volume(ml))…. For solids

Molarity(M)= (Sp.grafity x w/w% x 1000) / M.Wt(g/mole).. For liquids

1dL(diciliter) = 100mL

= (V)

Equivalent= is the mass of material providing Avogadro's number of reacting units.

Formality (F) is the No of formula weight of a solute dissolved in 1 L solution.

F= number of formula weight /L or F= mili formula weight/ml Example : Exactly 5.00 g NaCl are dissolved in 100ml distilled water .calculate the formality of this solution?

No of formula weight= weight(gm) / gram F.Wt F.wt=5.00/58.44= 0.0856

Formality = 0.0856 /(100×0.001) = 0.856 gf.wt /L

Formality(F) is numerically the same as Molarity(M) . F is used for ionic salts that do not exist as molecules in the solid or in the solution. Formality = Molarity numerically F is used for total analytical concentration . M is used for equilibrium concentration.

Molality(m) = mole of solute/1000g solvent

The calculations of this type involved: 1- Convert the mass of compound to equivalent moles. 2- multiply by stoichiometric factor. 3- reconversion the data in mole to the metric units.

Thanks