CHEM 110 Chapter Notes - Chapter 5: Chemical Formula, Homonuclear Molecule, Molar Mass
Document Summary
Allotropes: have the same composition, but different structures (ex: different atom connectivity) Simplest assemblies are composed of just 2 atoms. If the same element = homonuclear diatomic molecules. Collections of identical atoms bonded into polyatomic molecules. Empirical formula: the simplest formula that gives the correct relative number of each kind of atom. Defines the smallest repeating unit of the composition. Molecular formula: the formula that specifies the number of each atom in one molecule. Defined only for substances that consist of well-defined molecules. Grams to moles divide by molar mass. % of element = (((number of moles) x atomic weight)/ molecular weight) x 100. Assume 100 g and convert percentage into grams (10% = 10 g) Divide mass of element by atomic mass of element. Divide the answer by the smallest value of moles of an element to get the ratio. The element with the smallest amount will always be 1.
