Question 1(multiple choice worth 3 points)
(06.06 mc)

what is the density of aluminum chloride vapor (alcl3) at 498 k and 0.939 atm?

a.1.24 g/l
b. 3.06 g/l
c. 5.17 g/l
d.7.42 g/l

= 3.064 g/L

Using the equation;

PV = nRT , where P is the pressure,. V is the volume, n is the number of moles and T is the temperature and R is the gas constant, 0.08206 L. atm. mol−1.

Number of moles is 1 since one mole has a mass equivalent to the molar mass.

Therefore; We can find the volume and thus get the density.

V = nRT/P

   = (1 × 0.08206 × 498 )/ 0.939

   = 43.52 L

But; density = mass/volume

Therefore;

Density = 133.34 / 43.52

             = 3.064 g/L

a rain shadow is a dry region of land on the side that is protected against the prevailing winds of a mountain range. the prevailing winds are the winds that occur most of the time in a particular place of the earth

prevailing winds carry air toward the mountain range. as the air rises up over a mountain range, the air cools, water vapor condenses, and clouds form. on this side of the mountains, called the windward side, precipitation falls in the form of  rain  or snow. this dry air produces a  rain shadow.

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.