You need to find which intermolecular forces are between the molecules
dipole-dipole,h bonds, etc.
I'm not very good at explaining but this is what my prof said to help us
Identify the class of the molecule or molecules you are given. Are they nonpolar species, ions or
do they have permanent dipoles? Is there only one species or are there two?
In the case of ONE species (i.e., a pure substance), the intermolecular forces will be between
molecules of the same type. So if you are dealing with ions, the intermolecular forces will be ION-
ION or IONIC. If you are dealing with dipoles, then the intermolecular forces will be DIPOLE-
DIPOLE. If you are dealing with nonpolar species, the intermolecular forces will be DISPERSION
or VAN DER WAALS or INDUCED DIPOLE-INDUCED DIPOLE (the last three are desciptions
of the same interaction; regrettably we cannot call them nonpolar-nonpolar!).
In the case of TWO species (i.e., a mixture), the intermolecular forces will be between molecules of
one type with molecules of the second type. For example, ION-DIPOLE interactions exist between
ions dissolved in a dipolar fluid such as water.
Answer : The correct option is, (b) 22.1 g
Solution : Given,
Mass of iron = 15.5 g
Molar mass of iron = 56 g/mole
Molar mass of 
= 160 g/mole
First we have to calculate the moles of iron.
Now we have to calculate the moles of .
The balanced reaction is,
From the balanced reaction, we conclude that
As, 2 moles of iron obtained from 1 mole of
So, 0.276 moles of iron obtained from 
mole of
Now we have to calculate the mass of
Therefore, the amount of required are, 22.1 grams.
Al:ch2 an molar ratio.
2:3 and an x. X is 30. 20/2 = 10 so an answer is
45/3 = 15. Both ratios are used
45 - 30 = 15 CL2 left.
Your Welcome :)
The answer is (1) CaCO3. The bond between C and O is covalent bond. And the bond between Ca2+ and CO3 2- ion is the ionic bond. So the compound CaCO3 satisfy this condition.
