Density of a 1.5 M solution of urea in water is 1.02
g/mL. The molality of the solution is
1.6 m
1.5 m
0.16 m
16 m
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Answered by
1
Answer:
Option 1 is correct ie. 1.6 m
Direct formula is see in
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Answered by
4
Given:-
→ Molarity of the solution = 1.5 M
→ Density of the solution = 1.02 g/mL
To find:-
→ Molality of the solution
Solution:-
• Chemical formula of urea = CH₄N₂O
• Molar mass of Carbon(C) = 12g
• Molar mass of Hydrogen(H) = 1g
• Molar mass of Nitrogen(N) = 14g
• Molar mass of Oxygen (O) = 16g
Hence, molar mass of urea is :-
= 12 + 1×4 + 14×2 + 16
= 12+4+28+16
= 60g
The relationship between molarity and molality is given by :-
=> m = 1000M/1000ρ - MMₘ
Where:-
• m is molality
• M is molarity
• ρ is density of the solution
• Mₘ is molar mass of solute
=> m = 1000×1.5/[1000×1.02 - 1.5×60]
=> m = 1500/[1020 - 90]
=> m = 1500/930
=> m = 1.6
Thus, molality of the solution is 1.6 m .
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