Relative Masses and Chemical Formulas Flashcards
1
Q
What is the relative formula mass (Mr) of a compound?
A
The relative atomic masses (Ar) of all the atoms in its formula added together.
2
Q
How to calculate the relative formula mass of a compound?
A
Use the periodic table to work out the Ar of the element for every atom in the compound, and add them all together.
3
Q
What is the Mr of a compound equal to?
A
The Mr of a compound is equal to the mass in grams of 1 mole of the compound.
4
Q
What is the empirical formula of a compound?
A
The smallest whole number ratio of atoms in the compound.
5
Q
How do you calculate the empirical formula?
A
Divide all of the numbers in the molecular formula by the largest number that goes into all of them.
E.g. glucose, C6H12O6, would be dividing 6, 12 and 6 by 6.
