Answer:
Molarity = 4.79 M
Explanation:
Mass percentage -
Mass percentage of A is given as , the mass of the substance A by mass of the total solution multiplied by 100.
i.e.
mass % A = mass of A / mass of solution * 100
Given,
24% by mass of ammonium chloride,
so,
100 g solution contains , 24 g of ammonium chloride,
mass of solution = 100g
and mass of the solute , i.e. , ammonium chloride = 24 g .
Hence,
Moles -
Moles are calculated as the given mass divided by the molecular mass.
i.e. ,
moles = ( mass / molecular mass )
Given,
The molecular mass of ammonium chloride is 53.50 g /mol
moles of ammonium chloride = 24 g / 53.50 g /mol
moles of ammonium chloride = 0.449 mol
Density -
Density of a substance is given as the mass divided by the volume ,
Density = mass / volume ,
Volume = mass / density
Given ,
Density of ammonium chloride = 1.0764 g /mL
Calculated above , mass of solution = 100 g
volume of solution = 100 g / 1.0764 g/ mL
volume of solution = 93.69 mL
Since , 1 ml = 1/1000 L
volume of solution = 93.69 /1000 L
volume of solution = 0.09369 L
Molarity -
Molarity of a solution is given by the moles of solute per liter of the solution
Hence,
M = moles of solute / volume of solution (in L)
As calculated above,
moles of ammonium chloride = 0.449 mol
volume of solution = 0.09368 L
Putting in the above formula
Molarity = 0.449 mol / 0/09368 L
Molarity = 4.79 M
