Answer:
The diameter of the oil molecule is
.
Explanation:
Mass of the oil drop = 
Density of the oil drop = 
Volume of the oil drop: v


Thickness of the oil drop is 1 molecule thick.So, let the thickness of the drop or diameter of the molecule be x.
Radius of the oil drop on the water surface,r = 41.8 cm = 0.418 m
1 cm = 0.01 m
Surface of the sphere is given as: a = 

Volume of the oil drop = v = Area × thickness


The thickness of the oil drop is
and so is the diameter of the molecule.
Answer : The mole fraction of NaCl in a mixture is, 0.360
Explanation : Given,
Moles of
= 7.21 mole
Moles of
= 9.37 mole
Moles of
= 3.42 mole
Now we have to calculate the mole fraction of
.

Now put all the given values in this formula, we get:

Therefore, the mole fraction of NaCl in a mixture is, 0.360
Answer: C = 0.014M
Explanation:
From n= m/M= CV
m =43.5 M= 148, V=850ml
43.5/148= C× 0.85
C= 0.35M
Applying dilution formula
C1V1=C2V2
C1= 0.35, V1= 25ml, C2=?, V2= 600ml
0.35× 25 = C2× 600
C2= 0.014M