C1 - Quantitative Chemistry Flashcards
What is relative formula mass?
The relative atomic masses of all the atoms in the molecular formula added together
What is the symbol of relative formula mass?
M (little) r
What is the symbol for relative atomic mass?
A (little) r
How do you find relative atomic mass?
It is the same as mass number
How do you find the relative formula mass?
Add up the relative atomic masses of all the atoms in the compound
How do you calculate the percentage mass of an element in a compound?
(A,r x number of atoms of that element) / (M,r of the compound) x 100
What is a mole?
In book
In a chemical reaction, mass is always?
Conserved
What happens to atoms in a chemical reaction?
Nothing, they can not be destroyed or created
What can cause mass to seem to change?
Gases
1 way gas makes mass seem to increase?
One of the reactants is a gas found in air, and the products are solid, liquid or aqueous. Before the reaction, you cannot account for the gas in the airs mass as it is floating around. When it reacts the gas becomes part of the product, causing a seemingly increased mass.
1 way gas makes mass seem to decrease?
One of the products is a gas and the reactants are solid, liquid or aqueous. Before the reaction, all the reactants are contained, but after, it is no longer contained and may cause the mass to appear to have decreased.
What are limiting reactants?
If one reactant gets completely used up in a reaction before the rest, stopping the reaction.
What is the amount of limiting reactant directly proportional to?
The amount of product formed.
At the same temperature and pressure, equal numbers of moles of any gas will occupy the same….
Volume
