SS1 Chem concentration -_-

1. No. of mole of 25.0 cm^3 of 0.1 M NaOH
= 25.0 X 0.1/ 1000 = 2.5X10^-3 mol


New concentration
= No. of mole of NaOH/ New volume
= 2.5X10^-3/ (250/ 1000)
= 1.0X10-2 M


2. Conservation of no. of mole of HCl
　　　　　M1V1 = M2V2
0.5 X 25.0/ 1000 = (0.5/10) X V2
　　　　　 　V2 = 2.5X10-1 m^3
　　　　　 　　 = 2.5 X 10^2 cm^3
The volume of the additional water = 2.5 X 10^2 - 25.0
　　　　　　　　　　　　 　　　= 2.25 X 10^2 cm^3