<span>Unsafe passes are passes with restricted line of sight, passes with cross traffic, narrow passes which are unsafe.
Several collision can result from making unsafe passes. Some of them are:
-getting run off the road
-getting sideswiped
-getting hit head-on</span>
Below are the choices that can be found elsewhere:
a. 268 kJ
<span>b. 271 kJ </span>
<span>c. 9 kJ </span>
<span>d. 6 kJ
</span>
So the key thing to realize here is what the information given to you actually means. Sublimation is going from a sold to a gas. Vaporization is going from a liquid to a gas. Hence you can create two equations from the information that you have:
<span>Ga (s) --> Ga (g) delta H = 277 kJ/mol </span>
<span>Ga (l) --> Ga (g) delta H = 271 kJ/mol </span>
<span>From these two equations, you can then infer how to get the melting equation be simply finding the difference between the sublimation (two steps) and vaporization (one step). </span>
<span>Ga (s) --> Ga (l) delta H = 6 kJ/mol </span>
<span>At this point, all you need to do is a bit of stoichiometry. You start with 1.50 mol and multiply by the amount of energy per mole (6 kJ/mol). </span>
<span>*ANSWER* </span>
<span>9 kJ/mol (C)</span>
