find the molarity of the solution where mole fraction of solute is 0.5000 and Molar Mass of Solute is 49 g/Mole and Molar mass of solvent is 18 g/M and density of solution is 1.769 g/ml.
Answers
Answer:
9
Explanation:
molecular weight of solute be =M
1
and molecular weight of solvent be M
2
fraction of solute =0.1
Let solution be litre
mass of solution 1 litre
mass of solution =2000 g
mass of solute =x man of solvent =2000−x.g
Molarity=
M
1
x
/1litre=
M
1
x
Molarity=
M
1
x
/(2000−x)×10
−3
=
(2000−x)M
1
1000 x
Molarity=Molarity
M
1
x
=
(2000−x)M
1
1000 x
2000−x=1000
x=1000 gM
number of mole of solute =
M
1
1000
number of mole of solvent =
M
2
1000
M
1
1000
+
M
2
1000
M
1
1000
⇒
M
1
+M
2
M
2
=0.1
M
2
=0.1M
1
+0.1M
2
0.9M
2
=0.1M
1
⇒
M
2
M
1
=9
Given: Mole fraction of solute is 0.5000, molar Mass of solute is 49 g/mol and molar mass of solvent is 18 g/mol and density of solution is 1.769 g/ml.
To find: Molarity of the solution
Explanation:0.5000 can be written simply as 0.5. Mole fraction of solute= 0.5
Let number of moles of solute be n1 and number of moles of solvent be n2.
Mole fraction of solute
= Number of moles of solute/ Total moles
=n1 / n1 + n2
Now,
n1 / n1+n2 = 0.5
=> n1 = 0.5 n1 + 0.5 n2
=> n1-0.5 n1 = 0.5 n2
=> 0.5 n1 = 0.5 n2
=> n1 = n2
Therefore, number of moles of both solute and solvent are equal.
Given mass of solvent
= number of moles * Molar mass
= n2 * 18
= n1 * 18 ( since n1 = n2)
Volume of solution
= Mass / Density
= n1 * 18 / 1.769
= 10.17 n1 mL
To convert this into L, we divide it by 1000.
Volume in L = 10.17 n1 /1000
= 0.01017 n1
Molarity
= Moles of solute/ Volume of solution in L
= n1 / n1 * 0.01017
= 98.32 M
Therefore, the Molarity of the solution is 98.32 M.