Why do soaps not work in hard water?

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) Soaps are sodium or potassium salts of long-chain fatty acids. Hard water contains calcium $(Ca^{2+})$ and magnesium $(Mg^{2+})$ ions. When soaps are dissolved in hard water,these ions displace sodium or potassium from their salts and form insoluble calcium or magnesium salts of fatty acids. These insoluble salts separate as scum.
$2C_{17}H_{35}COONa + CaCl_2 \to (C_{17}H_{35}COO)_2Ca + 2NaCl$
This is the reason why soaps do not work in hard water.

Explore More

Similar Questions

Give information on the uses of green chemistry in day-to-day life.

Difficult
View Solution

Which of the following statements are correct?
$a$. Aspartame is sweeter than saccharin
$b$. Shaving soaps contain glycerol to prevent drying
$c$. Salt of sorbic acid is used as a food preservative
$d$. Norethindrone is an example of an antifertility drug

Consider the following statements:
Statement-$I$: Shaving soaps contain glycerol to prevent rapid drying.
Statement-$II$: Laundry soaps contain sodium rosinate or sodium silicate as fillers,not sodium carbonate.
Correct answer is:

$A$ detergent is a

When soap is dissolved in hard water,its cleaning ability decreases. This is due to the formation of:

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo