1.2 Liquids and Solutions

Question 1

dilutions in a linear dilution series

Answer 1

differ by an equal interval

Question 2

dilutions in a log dilution series

Answer 2

differ by a constant proportion

Question 3

what is produced when measured values for known concentrations are plotted?

Answer 3

a standard curve

Question 4

what does a standard curve allow?

Answer 4

the concentration of an unknown to be determined

Question 5

effect of the addition of an acid/alkali on a pH buffer

Answer 5

the addition of an acid/alkali has a very small effect on the pH of a buffer

Question 6

what does a pH buffer allow?

Answer 6

the pH of a rection mixture to be kept constant

Question 7

colorimeter

Answer 7

finds the concentration of a coloured solution by measuring the absorbance of specific wavelengths of light by the solution

Question 8

how is a colorimeter calibrated?

Answer 8

by using a ‘blank’ cuvette containing only solvent, which acts as a baseline

Question 9

how is turbidity determined?

Answer 9

by measuring the percentage transmission of light

Question 10

turbidity

Answer 10

a measure of the levels of particles in a fluid eg. the levels of cells suspended in the fluid