Environment Studies

Temporary hardness caused due to

• Cl^-1

• ^SO₄^-2

• HCO₃^-1

• None of the above

Hardness caused due to

• Ca+2

• Mg+2

• Fe+2

• All of the above

Which indicator used to determine total hardness?

• Eriochrome Black T

• Calgon

• Phenolphthalein

• Litmas

Which indicator used to determine calcium hardness?

• Eriochrome Black T

• Calcon

• Phenolphthalein

• Litmas

Why 3M NaOH added for determination of Calcium hardness?

• To remove calcium ion

• To remove magnesium ion

• To remove total hardness

• None of the above