Chapter 16 - Analysis for Salts

Question 1

Absorbance

Answer 1

The measure of how much light a substance absorbs. Note: complementary colours are the most absorbed.

Question 2

Anhydrous

Answer 2

(of a compound) not containing water molecules. E.g. CuSO₄

Question 3

Calibration Curve

Answer 3

A graph obtained by plotting the absorbencies of standard solutions (linear).

Question 4

Colorimeter

Answer 4

A machine which shines light through a complementary coloured filter at a sample to measure its absorbance.

Question 5

Gravimetric Analysis

Answer 5

An analysis technique that measures the mass of a reactant or product to determine a quantity of unknown.

Question 6

Hydrated

Answer 6

(of a compound) containing water molecules. For example: CuSO₄·5H₂O

Question 7

Hydrated Salt

Answer 7

A salt that has water molecules absorbed into its crystal lattice. E.g. CuSO₄·5H₂O

Question 8

Water of Hydration (Water of Crystallisation)

Answer 8

Water molecules that are absorbed into a crystal lattice.

Question 9

Metal Complex (Colour Complex)

Answer 9

A chemical compound in which a metal ion is bound to a molecule or anion; coloured.

Question 10

Spectroscopy

Answer 10

The technique of using electromagnetic radiation to determine information about chemicals.

Question 11

UV-visible Spectrophotometer

Answer 11

A machine which shines an exact wavelength of visible light at a sample, to measure its absorbance.

Question 12

Colorimetry

Answer 12

Measuring the intensity of colour in a sample of solution to determine its concentration.

Question 13

Requirements for Colourimetry:

Answer 13

1. Solution is coloured
2. Solution is fully dissolved
3. Solution is stable