Exam Questions

Question 1

The bees method for separating a mixture of amino acids in solution is…

Answer 1

Chromatography

Question 2

Suggest why 1,4-dimethylbenzene is MORE reactive than benzene in reactions

Answer 2

The methyl groups give a greater electron density in the ring // Ring is activated // More susceptible to electrophilic attack

DUE TO - electron releasing / donating or the methyl groups

Question 3

Explain why the [Cr (H20)6 ]3+ ion is coloured??

Answer 3

Ligands cause d orbitals / sub shells / sub levels to split!!!

Some frequencies of light energy are absorbed

To promote electrons (within d-levels / d > d transitions)

Question 4

Half equations of ethandioic acid and potassium (Vll) under acidic conditions

Answer 4

MnO4- + 8H+ + 5e- &raquo_space; Mn2+ + 4H2O

(COOH)2 &raquo_space; 2CO2 + 2H+ + 2e-

Question 5

[Cr(H2O)6]3+ ions react with water to form an acidic solution. Whats the equation for this reaction??

Answer 5

[Cr(H2O)6]3+ +. H2O &raquo_space;

Question 6

In the solid state, the amino acid serine exists in the form….

Answer 6

H3N+ CH (CH2OH) CO2-

Question 7

What is a buffer??

Answer 7

A buffer is a solution that resists change in pH when small amounts of acid/alkali are added!!