Liquids and Solutions 1.1 Flashcards
what do linear dilutions consist of?
a range of dilutions that differ by an equal interval
what do log dilutions consist of?
a range of dilutions that differ by a constant proportion
what are standard curves used for?
to determine an unknown value
what is a buffer?
a solution where adding acids or alkalis have little effect on pH
how do buffers work?
it allows pH in a reaction mixture to be kept constant
what are colorimeters used for?
to quantify concentration and turbidity
what are colorimeters calibrated with and why?
they must be calibrated with a blank sample to provide a baseline reading
how does a colorimeters work?
light is passed through a sample solution where a detector picks up how much light has been absorbed by the sample or transmitted
what can absorbance determine?
concentration of a coloured solution using suitable wavelength filters
what does percentage transmission determine
turbidity - cells in suspension
how do linear dilutions work?
different volumes of stock solution are added to different solvents
how do log dilutions work?
each dilution acts as the stock dilution for subsequent dilution
