Question

If x g of a solute having molar mass M g/Mole v
present in yg of solution, then molality of x in the
solution should be​

Answer 1

Answer:

correct ans is C

Explanation:

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>>If M is the molarity, d is the density (

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If M is the molarity, d is the density (in g/ml), M

B

is the molar mass of solute and m is the molality, then choose the correct relation ?

Hard

Solution

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Correct option is C)

Given that

Density of the solution =d (in gm/ml)

Molarity of the solution =M

Molar mass of the solute =M

B

(in gm/mol)

Let's take 1000 ml of the solution, then

Mass of the solution = Volume (ml) × density

= 1000 ml × d gm/ml = 1000 d gm

Moles of solute =M×Volume=M×1lit=Mmoles (Since, 1000ml=1liter)

∴ Mass of the solute = No. of moles× Molar mass =MM

B

gm

∴ Mass of the solvent = mass of the solution − mass of the solute=(1000d−MM

B

) gm

Now,

Molality (m) =

Kilogramsofsolvent

molesofsolute

∴ m=

(1000d−MM

B

)×

1000

1

M

⇒m=

1000d−MM

B

1000M