Question

1.9 Calculate the molar mass for each of the following: a. KC4​H5​O6​ (cream of tartar) b. Fe2​O3​ (rust) c. C19​H20​FNO3​ (Paxil, an antidepressant) d. Al2​(SO4​)3​ (antiperspirant) e. Mg(OH)2​ (antacid)

Answer 1

consider how many atoms of each element are in the molecule, and then multiply it by its molar mass

a. KC4H5O6 = 39.1 + (12.0×4) + (1.01×5) + (16.0×6) = 188

b. Fe2O3 = (55.8×2) + (16.0×3) = 160

c. C19H20FNO3 = (12.0×19)+(1.01×20)+(19.0×1)+(14.0×1)+(16.0×3) = 329

d. Al2(SO4)3 = (27.0×2)+{[(32.1×1)+(16.0×4)]×3} = 342

e. Mg(OH)2 = 24.3 + [(16.0+1.01)×2] = 58.3