Which one of the following compounds is a carboxylic acid?    

Complete the following sentence: ‘Different isotopes of the same element have…’ 

Two atomic orbitals will overlap to form how many molecular orbitals?  

Oxygen has an atomic number of 8. Which one of the following shows the correct electronic configuration of an atom of oxygen?  

What type of intermolecular force is being shown in the this interaction?  

Which one of the following species behave as an nucleophile?

Which one of the following statements about disulfide bonds is False?

Match the protein form to the correct structural type.

Which one of the following compounds is chiral?  

The concentration of compound X is measured at different time intervals during the course of a chemical reaction. After plotting a graph of the concentration of X against time, shown below, the points labelled A-E on the graph have the following co-ordinates: A: x = 0 seconds; y = 0 mol L-1 B: x = 8 seconds; y = 0.37 mol L-1 C: x = 15 seconds; y = 0.49 mol L-1 D: x = 23 seconds; y = 0.63 mol L-1 E: x = 30 seconds; y = 0.60 mol L-1   What is the rate of the chemical reaction at point C? This question is worth 3 marks.