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QJEEM21Ch6dd1: JEE Main 2021 Chemistry - Class 11 JEEM21Ch6dd1 Solution: The density of NaOH solution is 1.2 g cm 3 . The molality of…

The density of NaOH solution is 1.2 g cm −- 3. The molality of this solution is _____________ m. (Round off to the Nearest Integer)

[Use : Atomic mass : Na : 23.0 u, O : 16.0 u, H : 1.0 u, Density of H2O : 1.0 g cm −- 3]

Step-by-Step Verified Solution

Consider 1 litre solution

mass of solution = (1.2 ×\times 1000)g = 1200 gm

Neglecting volume of NaOH

Mass of water = 1000 gm

⇒\Rightarrow Mass of NaOH = (1200 −- 1000)gm = 200 gm

⇒\Rightarrow Moles of NaOH = 200g50g/mol=5{{200g} \over {50g/mol}} = 5 mol

⇒\Rightarrow molality = 5mol1kg=5{{5mol} \over {1kg}} = 5 m

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