1) b) liquids and solutions

Question 1

describe a linear dilution

Answer 1

Dilutions in a linear dilution series differ by an equal interval
for example 0·1, 0·2, 0·3 and so on.

Question 2

describe a log dilution

Answer 2

Dilutions in a log dilution series differ by a constant proportion
for example 10-1, 10-2, 10-3 and so on.

Question 3

Describe the addition of an acid or an alkali on a pH buffer

Answer 3

Addition of acid or alkali has very small
effects on the pH of a buffer, allowing the pH of a reaction mixture to be kept constant.

Question 4

Absorbance is used to _________________

Answer 4

use of absorbance to determine
concentration of a coloured solution using suitable wavelength filters

Question 5

Percentage transmission is used for _________
example of this is _________

Answer 5

use of percentage transmission to determine turbidity.
example - such as cells in suspension.

Question 6

How do you determine a concentration of an unknown of a solution

Answer 6

Plotting measured values for known
concentrations to produce a line or curve allows the concentration of an unknown to be determined from the standard curve