Unit 1.1.b

Question 1

What are linear dilutions?

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

What are log dilutions?

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

What does the production of a standard curve allow?

Answer 3

The concentration of an unknown to be determined from the standard curve

Question 4

What effect does the addition of acid or alkali have on pH of a buffer

Answer 4

Small effect, the pH of a reaction mixture to be kept constant

Question 5

What are methods and uses of a colorimeter to quantify concentration and turbidity

Answer 5

Calibration with appropriate blank as a baseline; use of absorbance to determine concentration of a coloured solution using suitable wavelength filters; use of percentage transmission to determine turbidity, such as cells in suspension.