unit 3 KA5 - chemical analysis Flashcards
what is chromatography
a technique used to separate the components present within a mixture
how does chromatography separate the components within a mixture
by making use of differences in their polarity or molecular size
what can be indicated, depending on the type of chromatography used
the identity of a component can be indicated either by the distance it has travelled, or by the time it has taken to travel through the apparatus
what is retention time
the time the component has taken to travel through the apparatus
the results of a chromatography experiment can sometimes be presented graphically. what does it show on each axis?
- an indication of the quantity of substance present on the y-axis
- retention time of the x-axis
what does volumetric analysis involve
using a solution of accurately known concentration in a quantitative reaction to determine the concentration of another substance
what is titration used to determine accurately
the volumes of solution required to reach the end-point of a chemical reaction.
what is an indicator normally used to show
when the end-point is reached
when are volumes considered concordant
when they are within 0·2 cm3 of each other
what are standard solutions
solutions of accurately known concentration
what are redox titrations based on
redox reactions
is an indicator required in titrations using acidified permanganate
no, because purple permanganate solution turns colorless when reduced
given a balanced equation for the reaction occuring in a titration, what can be calculated?
- the concentration of one reactant
- the volume of one reactant
how can the concentration of one reactant be calculated, given a balanced equation for the reaction occurring in any titration?
it can be calculated given the concentration of the other reactant and the volumes of both solutions
how can the volume of one reactant be calculated, given a balanced equation for the reaction occurring in any titration
it can be calculated given the volume of the other reactant and the concentrations of both solutions
