Calculate the number of moles in 23.0g of CO2? ( relative atomic mass : Carbon=12, Oxygen=16)
Firstly we need to work out the molecular mass of CO2 . There is one carbon and two oxygens so we have to add the relative atomic mass (Ar) of one carbon and two oxygens. From the question we know the Ar of Oxygen and Carbon so the relative formula mass (Mr) of CO2 is : RMM= 12 + (16 X 2) = 44g/mol
Using the equation m=Mr x n We can work out the number of moles but first we have to rearrange the equation to give n on one side. So divide both sides to give : m/Mr=n From the question we know the mass of CO2 and the Mr ,so plug these into the equation to give a value for n.
23g/44g/mol=0.52 moles ( given to 2 significant figures)
DB
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