Techniques

Question 1

elemental microanalysis

Answer 1

used to determine the masses of C,H,O,S and N in a sample of an organic compound so as to find the empirical formula

Question 2

mass spectrometry

Answer 2

small sample of organic compound is bombarded by high-energy electrons, which will break the molecule down into positively charged ion fragments

Question 3

infrared spectroscopy

Answer 3

used to identify functional groups in a compound

Question 4

infrared radiation and bonds

Answer 4

bonds within the molecule vibrate (stretch and bond). the wavelengths of infrared radiation absorbed depend on the type of atoms that make up the bond and the strength of the bond

Question 5

proton NMR

Answer 5

gives information about the different chemical environments of hydrogen atoms in an organic molecule, and about how many hydrogen atoms are in each environment

Question 6

integration curve of NMR graph

Answer 6

proportional to the number of H atoms in that environment

Question 7

multiplet

Answer 7

the number of H atoms on neighbouring carbon atoms will determine the number of peaks within a multiplet in the NMR graph

Question 8

ppm

Answer 8

1 mg per kg or 1 mg per litre

Question 9

heating to constant mass

Answer 9

heat the substance; allow to cool in a desiccator to prevent absorption of water; weighing; repeating steps until no further changes in mass are observed

Question 10

gravimetric analysis

Answer 10

used to determine the mass of an element or compound in a substance

Question 11

standard solution

Answer 11

a solution of accurately known concentration

Question 12

preparation of a standard solution

Answer 12

weighing a primary standard; dissolving in a solvent; transferring solution and rinsings into a volumetric flask; making up to the graduation; stoppering and inverting