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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Hardness of water is expressed as milli-equivalent per litre (mEq/L), one unit of which is equivalent to which one of the following -
assistant
The correct answer is  Hardness of water us expressed in milliequivalents/L. One mEq/L is equal to 50mg of CaCO3(50 ppm) in one litre. Park's Textbook of Preventive and Social Medicine, 25th edition, Page No. 786