Solution Stoichiometry

Question 1

Review: Stoichiometry

Answer 1

What is stoichiometry used for?

To predict the quantity of one reactant required to completely react with another

To predict the quantity of product formed from given quantities of reactants (we had a flowchart for this!)

To predict the quantity of reactant(s) required to form a desired quantity of product

We did all of these calculations in Unit 3!

Question 2

Solution Stoichiometry

Answer 2

Instead of starting/ending our calculations with masses, we will start/end our calculations with volumes and concentrations
Why? Because a lot of chemical reactions occur in aqueous solution!

Question 3

Stoichiometry of ions in solution

Answer 3

Sometimes, we might be interested in the concentration of a particular ion rather than the concentration of the compound that the ion is found in
To determine an ion’s concentration, we must consider its dissociation equation
For example, consider this dissociation of CaCl2:
Since the mole ratio of Ca2+ to Cl- is 1:2, when CaCl2 dissociates, there are twice as many Cl- ions in solution as Ca2+ ions
So, if the concentration of Ca2+ is (for example) 3 mol/L, then the concentration of Cl- must be 6 mol/L