Detergents are sodium of potassium salts of sulphonic acids. Phosphates are added to commercial detergents because they form complex with metal ion that contributes water hardness and keep them dissolved. They also control acidity and micelle formation. Phosphates arediscouraged because there is overgrowth of vegetation and decay of dead plants reduceamount of dissolved oxygen. 
1 mole of `[AgI]Ag^(+)` sol is coagulated by 

Options

A. 1 mole of KI
B. `500ml of 1 M K_2SO_4`
C. 1 lit of 1 M KI
D. None

Answer

A, B, C

Explanation

One mole of` [AgI]Ag^(+)` is coagulated by 1 mole of `I^(+)`.
` [AgI] Ag^(+) + I^(-) to AgI + AgI , 2[AgI] Ag^(+) + SO_(4)^(2-) to 2AgI + Ag_2 SO_4`
`2 "mole" to 1 "mole" , 0.5 " mole" `
500ml of `1 MK_2 SO_4 = 0.5` mole Thus b is true
1 lit of `1 MKI = 1` mole `I^(-)` Thus c is true