Q: 41 (NDA-I/2013)


Which of the following statements regarding the property of hard water is/are correct?
1. Temporary hardness of water is due to the presence of soluble magnesium and calcium hydrogen carbonate.
2. Temporary hardness of water can be removed by boiling.
3. Calgon's method is applied to remove temporary hardness of water.
4. Permanent hardness of water is removed by Clark's method.
Select the correct answer vising the code given below,
question_subject: 
Science
question_year: 
2013
question_exam: 
NDA-I
stats: 
0,568,920,576,520,264,128