topic 5 - amounts of substance Flashcards
theoretical yield definition
the maximum possible mass of a product, assuming there was a complete reaction and no transfer losses
what are the 3 reasons why the actual yield is less than the theoretical yield
-incomplete reaction, either because not all the reactants reacted or the reaction is reversible
-side reactions lead to unwanted products
-impurities in the product so it may need to be purified, leading to a loss of product
-practical losses when transfering the reactants/products between different equipment
percentage yield equation
actual yield/theoretical yield x 100
actual yield definition
the actual mass of products obtained from a reaction by weighing
what 5 factors do industries need to take into account when deciding the suitability of an industrial process
-atom economy
-percentage yield
-availability of raw materials
-cost of raw materials
-amount of energy needed
equation for atom economy
molar mass of desired product/molar mass of all products x 100
molar mass means the relative molecular mass times the molar ration (so you include the big number when working out the RMM of the compounds)
what is the atom economy of addition reactions, why
100% because there is only 1 product so all the atoms in the reactants are used to make the desired product
Definition of a mole
The amount of substance that contains the same number of particles as the number of carbon atoms in exactly 12g of the carbon12 isotope
what can we say about the atom economy of elimination, substitution and multistep reactions
they have lower atom economies
Avogadro’s constant definition
The number of atoms of carbon12 in exactly 12g of carbon12
