Unit 1 Part 1b (Liquids And Solutions)

Question 1

Describe linear dilutions

Answer 1

Differ by an equal interval (0.1, 0.2, 0.3)

Question 2

Describe log dilutions

Answer 2

Differ by a constant proportion

Question 3

How can a standard curve be used to determine an unknown?

Answer 3

By 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

Question 4

How can a buffer be used to control pH?

Answer 4

The addition of an 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 5

How can a colorimeter be used 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