Differences in boiling points between molecules are due to varying strength of intermolecular forces. From the data given, we know Br2 must have the strongest intermolecular forces as it has the highest boiling point, followed by NH3 and then F2.

iodine

Larger size means there are more electrons available to form the dipoles. Cl is lower on the Table. It has 3 energy levels while F has only 2 energy levels. So Cl2 is larger than F2.

In short “The more electrons a molecule has, the stronger the London dispersion forcesare. For example, bromine, Br2, has more electrons than chlorine, Cl2, sobromine will have stronger London dispersion forces than chlorine, resulting in a higher boiling point for bromine, 59 oC, compared to chlorine, –35 oC.”

I2 has a larger mass and much more electrons. Thus Van der Waals forces in I2 are stronger and boiling point is higher. The boiling point is a measure for intermolecular forces, the stronger these forces the higher boiling point.

Dipole-dipole interactions

In order from strongest to weakest, the intermolecular forces given in the answer choices are: ion-dipole, hydrogen bonding, dipole-dipole, and Van der Waals forces.

London dispersion force

HF (boiling point = 19.4 degrees Celsius) has the strongest intermolecular forces. The boiling point of a compound is directly related to…

As fluorine has small size and high electronegativity, it has high tendency to attract partial positive charge accumulated on H-atom. So, fluorine forms strongest H-bond.

hydrogen bonding

The strongest hydrogen bond type is the one involving a bond between oxygen, nitrogen and fluorine, with a hydrogen atom. Since in the choices, only water shows a O-H bond, therefore this is the strongest hydrogen bonding. The answer is water.

HF

oxygen

Ion-ion forces (attraction between two ions) are the strongest interactions overall. Hydrogen bonding, an attraction between a hydrogen atom and a highly electronegative atom like fluorine, oxygen, or nitrogen, is the second strongest interaction listed.

London-dispersion forces

hydrogen bonds

Acetone does not have hydrogen bonding because there are no hydrogens bonded directly to the oxygen which would give the needed strength of dipole…

The oxygen in acetone is partially negative and the H atom in water is partially positive. They will be attracted to form a hydrogen bond.

Although formaldehyde doesn’t engage in strong hydrogen bonds by itself, in the presence of water or another protic compound — one that contains a very positive hydrogen, such as H2O, HF or NH3 — strong hydrogen bonds do form.

The fundamental examples of hydrogen-bonding molecules have been H2O, HF, and NH3. Although NH3 vigorously accepts hydrogen bonds in the gas phase, there is yet no example in which NH3 acts as a hydrogen-bond donor.

Hydrogen bonding between a water molecule and an ammonia (NH3) molecule. Note that the N atom in the NH3 molecule is attracted to a H atom in the H2O molecule. At 25oC, nitrosyl fluoride (ONF) is a gas whereas water is a liquid….

This is an ionic compound because the chlorine atom is attached to the carbon atom, so the electronegativity difference is more. So there is an ionic bond that exists between C-Cl. For carbon and hydrogen, three sigma bonds are present and one between carbon and chlorine. …

Ammonia (NH3) has polar covalent bond.

The ammonia molecule is held together by the strong N–H nitrogen–hydrogen single covalent bonds by sharing electrons.

In NH3 molecule N has a lone pair of electron and in BF3 molecule B has an incomplete octet. has a double bond and two lone pair of electrons. It gives one of the lone pair to the third O atom. Thus, O3 is formed by a double bond a co-ordinate covalent bond.

– In the molecule NH3 the structure has a lone pair of electrons present on its central nitrogen atom which can give it to form a dative bond. Hence, NH3 shows the dative bonding.

one hydrogen ion is transferred from HCl to the lone pair on NH3 . This particular hydrogen only has its nucleus transferred—its electrons remain with chlorine. So, the bond between this particular hydrogen atom and the central nitrogen is a dative covalent bond.

The lone pair of electrons on nitrogen shares their electron with hydrogen to form dative bonds. On the other hand CO2 has covalent bond and no lone pair of electrons and NaCl and PCl5 are having ionic bonds present in them.

Lewis Dot of Hydronium H3O+ Hydronium is the positive ion present in Arrhenius acid solutions. Hydronium contains 2 polar covalent bonds and 1 coordinate covalent bond.