Why hard water does not give lather with soap ?

examrobotsa's picture
Q: 52 (CDS-I/2013)
Why hard water does not give lather with soap ?

question_subject: 

Science

question_exam: 

CDS-I

stats: 

0,33,17,33,14,3,0

keywords: 

{'lather': [0, 0, 0, 1], 'hard water': [0, 0, 0, 2], 'soap': [0, 0, 0, 3], 'ph': [3, 0, 3, 3], 'chloride ions': [0, 0, 0, 1], 'mg ions': [0, 0, 0, 1]}