To a 4L of 0.2M solution of `NaOH, 2L` of `0.5M NaOH` are added. The molarity of resulting solution is

To a 4 L of 0.2 M solution of NaOH, 2L of 0.5 M NaOH are added. The molarity of the resulting solution is :

50 ml of 0.1 M HCl and 50 ml of 0.2 M NaOH are mixed. The pH of the resulting solution is :

2.5 litre of 1M NaOH solution is mixed with another 3 litre solution of 0.5M NaOH solution. Then the molarity of the resulting solution is

50 mL of 0.1 M HCl and 50 mL of 2.0 M NaOH are mixed. The pH of the resulting solution is