Propanoic acid, methanoic acid and ethanedioic acid are all weak acids.

1. (a)Draw the displayed formula of ethanedioic acid.[1]
2. (b)The three acids, propanoic acid, methanoic acid and ethanedioic acid, can be distinguished using a combination of two chemical tests. Neither testing reagent is an acid-base indicator. Identify two suitable testing reagents and complete Table 10.1 to show the observations from each test. reagent 1 ...................................................... reagent 2 ...................................................... Table 10.1 observation when treated with reagent 1 observation when treated with reagent 2 propanoic acid methanoic acid ethanedioic acid[4]
3. (c)When propanoic acid is treated with chlorine gas in the presence of ultraviolet light, a mixture of products is formed. One of these products is 2,2-dichloropropanoic acid. Explain why 2,2-dichloropropanoic acid is stronger than propanoic acid. Refer to the structure of each compound in your answer.[2]