Topic 5: Quantitative analysis Flashcards
How is concentration in mol/dm3 calculated?
concentration = moles of substance / volume of solution (dm3)
What is concentration?
The amount of solute in a solution
What are the units of concentration?
g/dm3 or mol/dm3 (grams per decimetre cubed or moles per decimetre cubed)
How do you convert cm3 to dm3?
divide by 1000
How do you convert concentration in g/dm3 to concentration in mol/dm3
divide by atomic or formula mass
What is percentage yield?
A measure of how much product is made in a reaction, compared to how much could be made in theory.
How is percentage yield calculated?
Percentage yield = actual yield /theoretical yield x 100
What is theoretical yield?
The maximum amount of product which could be made
What is actual yield?
The amount of product actually produced by a reaction
Why is percentage yield never 100%?
The reaction may be incomplete, mass may be lost by evaporation, some mass might be left in reaction container, side reactions might take place, the reaction might be reversible
What is atom economy?
What proportion of the products of a reaction are the desired product
What is a desired product?
The chemical produced by a reaction which is wanted
How is atom economy calculated?
atom economy = atomic or formula mass of desired product / total atomic and formula masses of all products x 100
When choosing a particular reaction pathway, what needs to be taken into account?
atom economy, percentage yield, equilibrium position and usefulness of byproducts
What is the molar volume of a gas?
The volume occupied by one mole of the gas at room temperature
