Question

Unit 5: Stoichiometry Study Guide

1. What is molar mass? How is it calculated? Provide an example,
2. What is percent composition? How is it calculated? Provide an example.
3. 1-step conversions: grams to moles/moles to grams & particles to moles/moles to particles. Give
calculations examples of each
4. 1-step conversion: mole to mole using a balanced chemical equation. Give calculations example
5. 2-step conversions: grams to particles/particles to grams. Give calculations examples of each
6. 3-step conversions using mole bridge map. Give at least two examples of calculations

Answer 1

1.Molar mass is the mass of a given substance divided by the amount of that substance, measured in g/mol. For example, the atomic mass of titanium is 47.88 amu or 47.88 g/mol. In 47.88 grams of titanium, there is one mole, or 6.022 x 1023 titanium atoms.

2.Percentage composition of a compound is a ratio of an amount of each element to the total amount of individual elements in a compound, which is then multiplied with 100. Let us take an example of H2O i.e. Water. Water has 2 molecules of hydrogen, and one mole of water is of 18.0152 grams.