(1) Define the following
(i) Molarity
(ii) Molality
(2) Determine the molarity of a solution of 4.0 gram per concentration of NaOH.

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Solution

Molarity: Molarity is defined as number of gram moles of solute dissolved in a litre of solution. It is denoted by M.
Molarity (M) $= \frac{Mass of solute in gram per litre}{Molecular mass of solute}$
(ii) Molality: Molality is defined as number of moles of solute present in a kilogram (1000 gram) of solvent. It is denoted by m.
Molality (m) $= \frac{Mass of solute in kg of solvent}{Gram molecular mass of solute}$
(2) Mass of NaOH = 40 gm.
Mass of salt = 4.0 gm
Number of moles of salt $= \frac{mass of salt}{molecular mass of salt}$
$= \frac{4}{40} = 0.1 m o l .$
Molality of solution $= \frac{Number of mol}{volume of solution}$
$= \frac{1}{1} = 0.1$

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(1) Define the following(i) Molarity(ii) Molality(2) Determine the molarity of a solution of 4.0 gram per concentration of NaOH.

(1) Define the following
(i) Molarity
(ii) Molality
(2) Determine the molarity of a solution of 4.0 gram per concentration of NaOH.