Potable water is generally considered satisfactory for mixing concrete. As a guide, the following concentrations represent the maximum permissible values:
1
To neutralize 100 ml sample of water, using phenolphthalein as an indicator, it should not require more than 5 ml of 0.02 normal NaOH.
2
To neutralize 100 ml sample of water, using mixed indicator, it should not require more than 25 ml of 0.02 normal H2SO4
3
Both A and B
4
None of the Above
5
Question Not Attempted