Lithium carbonate, li2co3, contains 18.8 % lithium and is used in the treatment of mental illnesses such as bipolar disorder. what mass of lithium is present in a 1.00-g dose of lithium carbonate?

Assuming that the 18.8% composition is based on mass, therefore the mass of Lithium would simply be the product of the fractional composition and the total dose. That is:

18.8 % = 0.188

mass Lithium = 0.188 * 1.00 g = 0.188 g

Answer:

0.188 g