Chapter 4 and 5 Reacting masses and Moles Flashcards
What does AR stand for
Relative atomic mass
AR definition
average mass of its isotopes, compared to 1/12th the mass of the carbon-12 atom.
2 laws of chemistry
Elements will always react in the same ratio to form a given compound
Total mass does not change
Therefore, mass of reactants = mass of products
What is a pure substance
A substance that only contains the particles shown in its formula
Purity formula (%)
(Mass of pure products)/(Total mass) * 100
What is one mole of particles (explanation)
Number of particles obtained by weighing out the Ar or Mr of the substance in grams.
What is the Avogadro constant
6.02*10^23
Symbol for 1 mole
mol
How many particles does 1 mol of a substance have??
1 mol of a substance has 6.02*10^23 particles in it
Formula of to find number of moles
number of mols = mass/MR
number of mols = Volume at atp/24 dm^3 (only gasses)
number of mols = concentration * volume
What is RTP
Room temperature (20 C) and pressure
Avogadro’s law
1 mole of every gas has the same volume. at RTP that volume is 24 dm^3
What is the concentration of a solution
2 units
Amount of solute that is dissolved in 1 dm^3 of solution.
mol/dm^3 or g/dm^3
What is the empirical formula
Simplest WHOLE NUMBER ratio in which atoms combine
What is the molecular formula
the ACTUAL whole number ratio in which atoms combine
