Question

Give one example of Dobereiner's law of triad.

Answer 1

Lithium \[\ce{(Li)}\], Sodium \[\ce{(Na)}\], and Potassium \[\ce{(K)}\] share comparable chemical properties and have increasing molecular masses of 6.9, 23.0, and 39.1 gm/mol, respectively. According to the law of triads, the molecular mass of sodium \[\ce{(Na)}\] should be equal to the average molecular mass of lithium \[\ce{(Li)}\] and potassium.