**Equivalent weight (EW) = Molecular weight (MW) / Valencey. (Z) **

**Normality (N) = Equivalent weight (EW) / Volume of Solution (1000 ml.) **

**Meq = Actual weight (W) / Equivalent weight (EW)**

*Example:*Molecular wt of K_{2}Cr_{2}O_{7} is 294.148 gm

Valency = 6 (because of Cr ^{-6})

EW = 294.148/6 = 49.025

N = 49.025/1000 ml = 0.049025.

To make 0.25 N solution = 0.25 x EW

= 0.25 x 49.025 = 12.256 gm. of K_{2}Cr_{2}O_{7} is required.

**Molarity = Molecular Weight, grams / One Liter of Distilled Water **

*Example: *

1 M NaCl = 58.5 gm NaCl in 1 Liter of D.W = 58500 mg/Liter

0.5 M NaCl = 29250 mg/Liter toxic for Bacteria