Washing with water doesn't remove grease stains from clothes but addition of detergent removes the molecules of greasy substances. Which property of liquid causes the above effect?

Washing with water doesn't remove grease stains from clothes but addition of detergent removes the molecules of greasy substances. A single drop of liquid is split into 8 identical drops. What will be the excess pressure in each drop?

Washing with water doesn't remove grease stains from clothes but addition of detergent removes the molecules of greasy substances. How can the coefficient of viscosity of a highly viscous liquid be determined by Stokes' method?

Water from a river can't be used for washing clothes by soap. So people there are using detergents.Give reason for this and suggest a remedy.

Ammonium chloride is used in the laboratory for the manufacture of ammonia : Which substance is used to remove the water content in ammonia. Which property is utilized here?

Some substances when dissolved in water cause hardness of water. Sodium chloride, Calcium bicarbonate, Calcium carbonate, Calcium sulphate, Magnesium sulphate, Calcium chloride, Magnesium carbonate. The hardness due to which of the above salts cannot be removed by boiling?