54.0 ml of a 1.2 m solution was diluted to a total volume of 228 ml
USing dilution equation
M1V1 = M2V2
Where M1V1 is before dilution while M2V2 is after dilution.
Therefore;
M1= 1.20 M, V2= 54 ml,
M2= V2 = 228 ml
1.20 M × 54 ml = M2 × 228 ml
M2 = (1.2 ×54)/ 228 ml
= 0.2842 M
0.2842 × 114 ml = M2 × (114 +111)
M2 = (0.2842 ×114)/ 225
= 0.143995
= 0.144 M