Moles and percentages Flashcards
1
Q
What is the amount of substance in a chemical reaction measured in?
A
Moles
2
Q
What is the molar mass of a substance?
A
The relative formula mass of the substance
3
Q
How do you calculate the number of moles?
A
Mass ÷ Molar mass
4
Q
Why might the mass at the end of the reaction be greater?
A
Gas has been gained from the air
5
Q
Why might the mass at the end of the reaction be lesser?
A
Water vapour or gas has escaped
6
Q
What is the empirical formula?
A
The simplest whole number ratio of each type of atom in a compound
7
Q
How many CM are in a DM?
A
1000
8
Q
How do you calculate concentration?
A
Mass of solute ÷ Volume of solvent
