Mole Concept and Stoichiometry

Question 1

What does Avogadro’s Law say?

Answer 1

For every 1 mole of particle, there are a total of 6 x 10^23 number of particles.

Question 2

What is the equation for calculating number of moles by using mass?

Answer 2

no. of moles = mass / Mr

Question 3

How many types of concentration units are there? What are they?

Answer 3

2 types. Molar concentration (mol/dm3) and mass concentration (g/dm3)

Question 4

What does the Avogadro Gas Law states?

Answer 4

For every 1 mole of any gas, the volume it takes up is 24dm3.

Question 5

What are the steps to solving stoichiometry questions?

Answer 5

1. Assess what is needed to be found, and what info is given.
2. Think backwards from what question is asking for, to all of the information given.
3. Write a balanced chemical equation.
4. Write the mole ratio from the chemical equation. (what you know : What you want to find).
   5 Write the mole ratio that shows the actual amount.
5. Use relevant mathematical equations to solve for what needs to be found.
   * Mr is always found in periodic table.
   * Always only compare 2 things at any one time in a mole ratio.
   * Always only compare in units of mol. Never in mass or volume or concentration etc. Only mol.