Table 1: Inhibition efficiency, corrosion rate, and surface coverage for aluminium in 0.1 N and 0.5 N hydrochloric acid solution with given inhibitor addition for 24 h at 298 ± 1 K.

Conc. Inh. (%)Inhibition efficiencyCorrosion rateSurface coverageInhibition efficiencyCorrosion rateSurface coverage
(0.1 N)(0.1 N)(0.1 N)(0.5 N)(0.5 N)(0.5 N)

Pet. Ether extract
0.1214.0213.270.140224.2529.270.2425
0.2419.6312.400.196327.6127.970.2761
0.3635.519.950.355135.8224.800.3582
0.4840.199.230.401942.5422.210.4254
0.6044.868.510.448648.1320.040.4813
Acetone extract
0.1212.1513.550.121519.0331.290.1903
0.2422.4311.970.224324.6329.130.2463
0.3641.129.080.411230.6026.820.3060
0.4845.798.360.457939.1823.500.3918
0.6051.407.500.514053.7317.880.5373
Methanol extract
0.1210.2813.840.102818.2831.580.1828
0.2416.8212.830.168222.7629.850.2276
0.3623.3611.820.233626.1228.550.2612
0.4829.9110.810.299136.1924.660.3619
0.6042.068.940.420647.7620.180.4776