In an experiment to study the rate of reaction between duralumin (alloy of aluminium, magnesium and copper) and hydrochloric acid 0.5g of the alloy were reacted with excess 4M hydrochloric acid. The data in the table below were recorded; use it to answer the question that follows:

Time ( minutes)	Total volume of gas cm3)
0	0
1	220
2	410
3	540
4	620
5	640
6	640
7	640

(a) (i) From the graph determine the volume of gas produced at the end of 2 ½ minutes ( 1 mk)

(b) Determine the rate of reaction between 3^rd and 4^th minutes ( 1 mk)

(c) Give a reason why some solid remained at the end of the experiment ( 2 mks)

(d) Given that 2.5m³ of the total volume of the gas was magnesium and aqueous hydrochloric acid, calculate the percentage mass of aluminium present in 0.5g of an alloy. (Al = 27) (H=1)

(e) State the properties of duralumin that make it more suitable than pure aluminum in aeroplane construction.