JAMB - Chemistry (2001 - No. 15)
The chemical used for coagulation in water purification is
Aluminium tetraoxosulphate (VI)
Copper tetraoxosulphate (VI)
Sodium tetraoxosulphate (VI)
Calcium tetraoxosulphate (VI)
Magyarázat
The most common chemical used for coagulation in water purification is aluminum tetraoxosulphate(VI), also known as alum.
CuSO\(_4\) is used as a fungicide, algaecide, herbicide, root killer, and soil additive. It can also be used to protect plants during seed treatment.
Na\(_2\)SO\(_4\) is used to dry organic liquids. As a filler in powdered home laundry detergents.
CaSO\(_4\) is used in tofu(a food prepared by coagulating soy milk and then pressing the resulting curds into solid white blocks of varying softness) as a coagulant.