Frequency = velocity (aka speed) / wave length
Very low gives free energy
Intermolecular forces are forces of interaction that are operative between two different molecules. They are of follow types
1) Dipole- dipole interaction
2) Hydrogen bonds
3) vander Waal's forces
Depending upon the polarity and constitution molecule above forces are operable.
for instance, in case of ammonia, Hydrogen bonds exist because hydrogen atom is attached to electronegative element i.e. N
HCl and CO are polar molecules, so dipole-dipole interaction is operative in these molecules.
Finally in case of CO2, vander Waal's forces of interaction is operable because it is a non-polar molecule.
Answer:
89.4%
Explanation:
Initially, there is 5.0 of the acetanilide in 100 mL of water, then the solution is chilled at 0ºC. The solubility represents the amount that the solvent (water) can dissolve of the solute (acetanilide). So, at 0ºC, 100 mL of water can dissolve till 0.53 g of the compound, the rest will precipitate and will be recovered.
So, the mass that is recovered is 5.0 - 0.53 = 4.47 g
The percent recovery is:
(4.47/5)x100% = 89.4%
The density is 3.144 g / cm^3.
<u>Explanation</u>:
If effective number of atom in NaCl type structure, z = 4
a = 705.2 pm ⇒ In centimeter = 705.2 
10^-10
Na = 6.023 10^23
density = (molecular weight) (z) / (Na) (a^3)
where molecular weight of KI is 166 g,
Z represents the atomic number
density = (molecular weight) (z) / (Na) (a^3)
= (166 4) / (6.023 10^23) (705.2 10^-10)
density = 3.144 g / cm^3.
