# Calculations

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• Empirical Formmula
• Calculations
• Calculating the percentage of an element within a compound
• Eg. Percentage of carbon in CO2
• Divide the R.A.M. of the element by the R.F.M. of the compound and times by 100
• 1) Carbon R.A.M=12                     2)CO2 R.F.M = 12(16x2)=44                     3)12 / 44 x100 = 27.3%
• Yield of Reaction
• How much product is made compared with the maximum amount that could be
• Eg. 2Mg + O2 =2MgO and 2.3g of MgO was collcted from 2.0g og Mg
• Using reactions with high yields in industry helps reduces waste and conserve resources such as oil, for energy so there is less pollution
• Not usually is all potential product is collected much is lost when collected or other reactions occur
• Percentage Yield= Amount of product collected / Maximum amount of product possible  x100
• The simplest ration of the atoms/ions in a compound
• Each elements R.A.M. is divided by the given percentage, and then divided again by the smallest number from the last sum
• Eg. Empirical formula of compound with 80% Carbon and 20% Hyrdogen
• Calculating Masses from equations
• We can use Balanced equations to calculate masses of reactants and products in a reaction
• Eg. 2Mg + O2 = 2MgO With 5g of Mg how much mass of MgO will be produced