Question

A `0.2075 g` sample of an oxide of cobalt on analysis was found to contain `0.1475 g` cobalt. Calculate the empirical formula of the oxide. `(Co = 59 "amu")`

Answer 1

Weight of `O = 0.2075 - 0.1475 = 0.06 g`
Mol of `Co = (0.1475)/(59) = 0.0025`
Mol of `O = (0.06)/(16) = 0.003`
Simplest ratio of `Co = (0.0025)/(0.0025) = 1.0`
Simplest ratio of `O = (0.003)/(0.0025) = 1.5`
Ratio of `Co : O = 1 : 1.5 = 2 : 3`
Formula `= Co_(2) O_(3)`