Q. Assuming that sea water is a 3.50 weight per cent aqueous solution of NaCl. What is the molality of sea water?
A) 0.062 m
B) 0.0062 m
C) 0.62 m
D) 6.2 m
Explanation
(c)
3.50 wt% of aqueous solution of NaCl means 100 g of sea water contains 3.50 g NaCl.
Water in sea water = 100-3.5 = 96.5 g
=0.0965 kg
Molality = $\frac{3.5}{58.5\ \times 0.0965}$
= 0.62 m
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.