Question 1

Chlorine, $\mathrm { Cl } _ { 2 }$ ,is a gas at room temperature,but bromine, $\mathrm { Br } _ { 2 }$ ,is a liquid.Explain.

Accepted Answer

Bromine atoms are larger than chlorine atoms, which means they have more electrons. This leads to stronger London dispersion forces (a type of van der Waals force), or induced dipole-induced dipole attractions, between bromine molecules compared to chlorine molecules. These stronger attractions make bromine a liquid at room temperature, whereas chlorine, with weaker attractions between its molecules, remains a gas.

Question 2

Why is the surface area of a gecko's foot so extensive?

Accepted Answer

The extensive surface area of a gecko's foot allows for a greater number of induced dipole-induced dipole forces of attraction to occur between the foot and the surface. This is what allows geckos to climb walls and ceilings, as their feet are able to create strong bonds with the surface they are clinging to.

Question 3

Plastic wrap is made of nonpolar molecules and is able to stick well to polar surfaces,such as glass,by way of dipole/induced dipole molecular attractions.How is it that plastic wrap also sticks to itself so well?

Accepted Answer

Plastic wrap is made of nonpolar molecules, which are unable to form dipole-dipole or ion-dipole attractions. However, they can form temporary induced dipoles through the movement of their electrons. When plastic wrap is pressed against itself, the induced dipoles of one side can interact with the induced dipoles of the other side, creating a stronger adhesive force through induced dipole-induced dipole attractions. Therefore, option D is the correct answer.

Question 4

Why are the melting temperatures of most ionic compounds far greater than the melting temperatures of most covalent compounds?

Accepted Answer

The answer of Why are the melting temperatures of most...

Question 5

Two chemical structures are shown,one of a typical gasoline molecule and the other of a typical motor oil molecule.Which is which?  Base your reasoning not on memorization but rather upon what you know about molecular interactions and the various physical properties of gasoline and motor oil.

Accepted Answer

The statement "greater induced dipole-induced dipole molecular interactions" refers to the fact that motor oil has a higher viscosity than gasoline. Viscosity is the resistance of a fluid to flow and is caused by intermolecular forces such as London dispersion forces between molecules. Therefore, a molecule with stronger intermolecular forces would have higher viscosity, and thus, B represents motor oil.

Question 6

Dipole-induced dipole forces of attraction exist between water and gasoline,and yet these two substances do not mix because water has such a strong attraction for itself.Which of the following compounds might best help to make these two substances mix into a single liquid phase? $\mathrm { Na } ^ { + } \mathrm { Cl } ^ { - }$

Accepted Answer

The answer of Dipole-induced dipole forces of attraction exist between...

Question 7

How are oxygen molecules attracted to water molecules?

Accepted Answer

Oxygen molecules ($\mathrm{O}_2$) are nonpolar, so they do not engage in dipole-dipole interactions or hydrogen bonding. Instead, they can be attracted to water molecules through induced dipole interactions, where the presence of a polar water molecule induces a temporary dipole in the oxygen molecule.

Question 8

List the following compounds in order of increasing boiling point: $\mathrm { Cl } _ { 4 }$ , $\mathrm { CBr } _ { 4 }$ , $\mathrm { CCl } _ { 4 }$ , $\mathrm { CF } _ { 4 }$ .

Accepted Answer

Boiling points increase with molecular weight and polarizability. $\mathrm{CF}_4$ has the lowest molecular weight and least polarizable halogens, leading to the lowest boiling point. $\mathrm{CCl}_4$, $\mathrm{CBr}_4$, and $\mathrm{Cl}_4$ (assuming a typo and referring to a compound with increasing halogen size) follow in increasing order due to their increasing molecular weights and polarizability.

Question 9

The boiling point of 1,4-butanediol is 230°C.Would you expect this compound to be soluble or insoluble in room-temperature water?

Accepted Answer

The answer of The boiling point of 1,4-butanediol is 230°C.Would...

Question 10

Consider the boiling points of the following compounds and their solubilities in room-temperature water.Why does the solubilities in water go down as the boiling points of these alcohols go up. $\quad $$\quad $$\quad $$\quad $$\quad $$\quad $ $\quad $$\quad $ 
$\begin{array}{llcc}\text { Boiling point: } & 65^{\circ} \mathrm{C} &\quad \quad \quad  117^{\circ} \mathrm{C} &\quad \quad \quad \quad \quad \quad  138^{\circ} \mathrm{C} \
\text { Solubility: } & \text { infinite } & \quad \quad \quad 8 g / 100 \mathrm{~mL} & \quad \quad \quad \quad 2.3g/ 100 \mathrm{~mL}
\end{array}$

Accepted Answer

The answer of Consider the boiling points of the following...

Quiz 15: How Atoms Bond and Molecules Attract

Chlorine, Cl2\mathrm { Cl } _ { 2 }Cl2​ ,is a gas at room temperature,but bromine, Br2\mathrm { Br } _ { 2 }Br2​ ,is a liquid.Explain.