# Quantitate chemistry

• Quantitate chemistry
• Relative Formula Mass
• Sum of the relative atomic masses of the atoms in the numbers shown in the formula
• Balanced equation= sum of the relative formula of the masses of the reactants = the sum of the relative formula masses of the products
• Number of atoms,molecules or ions in a mole= Avogadro Constant
• Moles
• Mass of 1 mole in grams is numerically equal to its relative formula mass
• 1 Mole of a substance contains the same number of the stated particles, atoms, molecules or ions as o1 mole of any other substance
• Avogadro Constant=6.02x10 to the power of 23
• Moles
• Mass of 1 mole in grams is numerically equal to its relative formula mass
• 1 Mole of a substance contains the same number of the stated particles, atoms, molecules or ions as o1 mole of any other substance
• Mass=moles/Mr
• Conservation of mass
• No atoms are lost/ made during a chemical equation so the mass of products = mass of reactants
• Reacting Mass
• Masses of reactants and products can be calculated from balanced equations
• Yield & Atom Economy
• It is not always possible to obtain the calculated amount of a product because:
• The reaction may not go to completion because the equation is reversible
• Some of the product may be lost when it is separated from the reaction mixture
• Some of the reactants may react in ways different to the expected reaction
• Amount of a product obtained is known as the yield
• %yield=mass of product actually made/ Maximum theoretical mass of product X100
• Atom Economy is a measure of the amount of starting materials that end up as useful products.
• Atom Economy=Relative formula mass of desired product from equation/ Sum of relative formula masses of all reactants from equation X100
• Gas Volumes
• Equal amounts in moles of gases occupy the same volume under the same conditions of temp and pressure
• The Volume of any gas at room temp and pressure is 24dm cubed
• Volume=  Mass of gas/ Mr of gas X 24