Density of 2M NaCI solution is 1.25 g/cc.The molality of the solution is :
Density of 2M NaCI solution is 1.25 g/cc.The molality of the solution is :
A. 2.79 molal
B. 0.279 molal
C. 1.279 molal
D. 3,85 molal
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Correct Answer - a
`"Mass of 3 M NaCI solution" = "density" x "volume" =(1.25g/ccxx1000cc)=1250g `
Molar mass of NaCI =58.5 g/mol
Mass of 3 moles of NaCI=`(58.5 g mol)xx(3 mol)=1.074 kg`
`"Molality of solution"=("No.of moles of NaCI")/("Mass of solvent in kg")`
`=((3mol))/((1.074 kg))=2.79 mol kg^(-1)=2.79 molal`
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