Calculation Formulae

1. Young’s Rule:                    Child dose = [Age X Adult dose] / (Age + 12)

2. Couling’s Rule:                  Infant dose = [Age (at next birthday) X Adult dose] / 24

3. Fried’s Rule:                      Infant dose = [Age (in months) X Adult dose] / 150

4. Clark’s Rule:                      Child dose = [Weight (in lbs) X Adult dose] / 150

D = M / V

Sp. gr. = Wt / V

Sp. vol = V / Wt         thus     sp. volume = 1 / sp. gr

Wt. of the liquid = sp. gr. of liquid X volume of the liquid

Volume of a liquid  =  Wt of liquid / sp. gr.

Strength X Volume = Strength X Volume

9 X ^oC = 5 X ^oF -160

Proof Gallon = Wine gallon X Proof strength / 50%

Sodium chloride        0.90%

Dextrose                     5.00%

Boric acid                   1.73%

Fp depression of normal saline is 0.52

The equivalent weight = Molecular weight / valency

m osmol = m moles X no of ions = (wt in mg / m wt) X no of ions

HLB  =

(Product 1 %  X  HLB1) + (Product 2 %  X  HLB2) + … Product 1 %  +  Product 2 %  +  …….

 

pH  =   – Log [ H⁺]

pOH =  – log [OH]

pH = pKw – pOH  = 14 – pOH

pKa = – log [Ka]

pKb = – log [Kb]

pH = pKa + log [ Salt / Acid ]

pH = pKa + log [ Base / Salt ]

pH = pKw – pKb + log [ Base / Salt ]

Sensitivity requirement = minimum quantity to be weighed in mg X permissible error

d X ^m  =   m X ^m-1

  d e ^2x = 2 e ^2x

I  X m . dx =

X m + 1   m + 1

+ C

  d ln X  = 1 / X

 

I  e 2x . dx  =

e 2x   2

+ C

 

  I   1 / X . dx  =  ln X  +  C

Ln e ^–x = – x ln e = – x