C3 Quantitative Chemistry

• Atom economy = (mass of product / total mass) x 100
• Percentage yield = theoretical yield / actual yield x 100
• Theoretical yield = moles of reactant x stoichiometric coefficient x molecular mass
• Mass is neither created nor destroyed in a chemical reaction
• Concentration = mass of solute / volume of solution
• Stoichiometry is the ratio of the number of atoms of each element in a chemical reaction.
• Empirical formula gives the simplest whole-number ratios of atoms of each element in a substance.
• The limiting reactant is the reactant that is used up first in a chemical reaction.
• Moles = mass / Molecular mass x 6.022 x 10^23 (Avagadro’s constant)
• volume of gas = moles x 24
• Mass = moles x molecular mass
• Percentage uncertainty = range / mean x 100
• Mass of the products can become less than the reactants if the reaction doesn't occur in an enclosed system. This is because external gases can bond with the other elements and internal gases can escape.
• Percentage mass of an element in a compound = molecular mass x number of atoms / Molecular mass of the compound x 100