Q1. Hydrogen can be manufactured by reacting methane with steam:



Calculate the atom economy for the reaction. You are given the Relative Atomic Masses of the elements as H = 1, C = 12, O = 16.


A1. From this information we can work out some Relative Molecular masses:


Methane (CH4) = 12 +1+1+1+1=16, Water (H2O) = 1+1+16 = 18, H2 (Hydrogen) = 1+1=2 and CO (Carbon Monoxide) = 12+16=28


Using the formula for Atom Economy:


Mrp = RMM of desired products

Mar = RMM total of all reactants.


We substitute:



Q2. Ethanol, CH3CH2OH, can be produced by the fermentation of glucose, C6H12O6:



Calculate the atom economy for the reaction. You are given the Relative Atomic Masses of the elements as H = 1, C = 12, O = 16.

A2. RMM Glucose = (6 x 12) + (12 x 1) + (6 x 16) = 180, Ethanol = (2 x 12) + (5 x 1) + (1 x 16) + (1 x 1) = 46

Q3. Nickel can be produced by the reduction of Nickel Oxide with Carbon, producing Nickel metal and Carbon Monoxide. Given the reaction for the equation:

And the relative atomic / molecular masses needed (Ni = 59, C = 12, O = 16), calculate the Atom Economy of this reaction.

A3. RMM of Nickel Oxide = 59+16 = 75 RAM of C = 12:

Q4. Magnesium metal can be produced by reacting Magnesium Oxide with Silicon according to the following reaction:

Given the RMM and RAM of the elements and compounds concerned, what is the Atom Economy of this reaction? (Si = 28, Mg = 24, O = 16)

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