Chem Unit Test 3 Flashcards
What is a mole?
The amount of a substance that contains 6.02 x 10^23 particles.
What is Avogadro’s constant?
6.02 x 10^23.
What is the Molecular formula?
A formula indicating the number of atoms of each element in a molecule.
How do you find the molecular formula from the empirical formula?
Divide the experimental (given) molar mass by the molar mass of the empirical formula. Multiply the empirical formula by the number you get.
What is a hydrate?
An ionic compound (salt) with a specific number of water molecules bonded to each formula unit.
How do you find the % H2O of a hydrate?
Divide the mass of the water by the total mass of the hydrate and multiply it by 100.
What is stoichiometry?
The study of quantitative relationships among the amounts of reactions used and the amounts of products formed in a chemical reaction.
How do you find the theoretical yield?
- Balanced equation.
- Mass to moles.
- Multiply by mole ratio.
- moles to mass.
What is the limiting reactant?
The reactant that runs out first in a chemical reaction.
What is the theoretical yield?
The expected amount of product in a chemical reaction.
Which reactant is the limiting reactant?
The one that gives you the smaller amount of moles.
What would you be saying if you chose the reactant that gave you more moles as the limiting reactant?
That the reaction can continue even if you have none of the limiting reactant left.
What is the actual yield?
The amount of product recovered in an experiment.
What do you want percentage yield to be?
As close to 100% as possible.
What is the formula for %y?
%y=(ay/ty)100
