C4 Flashcards
(12 cards)
What is the law of conservation of mass
Total mass of reactants = total mass of products
What is the relative atomic mass
That average mass of the atom
How to calculaye the relative formula mass of a compound?
Need to know the relative atomic mass (Ar)of the elements that make the compound and then multiply the Ar values by the number of atoms of that element in the compound. After, you add the number together
Why after 2 elements react is the mass less?
Some gas has escaped into the surroundings
Why must chemical equations be balanced ?
To make sure there are the same number of atoms of each elements before and after a reaction
What does the molecular formula show?
The actual amount of atoms which make up a molecule
What does the empirical formula show
The simplest ratio of atoms which make up a molecule
What is avogadro constant
6.02 x10^23
Number moles =
Mass/ mr
What is the limiting reactant
The reactant that is completely used up
Concentration =
Moles / volume
How to make sure there’s no acid left
Use an excess amount of the reactant
