# 78 Consider the following elementary steps; which would be the least likely to occur?

a) X + Y -> Z
b) 2X + Y -> Z
c) 2X + 2Y -> W + Z
d) 2X -> X + Y
e) 2X + Y -> 2W + Z

can someone please explain this to me. The ANSWER is: C.
the answer says its something about "Fruitful collision" what is that supposed to mean

#118 How many lone electron pairs are found in AsBr3?

a) 8
b) 10
C) 12
d) 6
e) 2

Answer: B Isn't this Q an error? Because As = 5 Br = 7 x 3 = 21. Therefore giving a total of 26. This results in 8 e- pairs around the As orbital; 1 being a lone pair. Maybe I'm thinking this TOTALLY wrong....

I'd greatly appreciate the help thank youu!!

# 78 Consider the following elementary steps; which would be the least likely to occur?

a) X + Y -> Z
b) 2X + Y -> Z
c) 2X + 2Y -> W + Z
d) 2X -> X + Y
e) 2X + Y -> 2W + Z

can someone please explain this to me. The ANSWER is: C.
the answer says its something about "Fruitful collision" what is that supposed to mean

#118 How many lone electron pairs are found in AsBr3?

a) 8
b) 10
C) 12
d) 6
e) 2

Answer: B Isn't this Q an error? Because As = 5 Br = 7 x 3 = 21. Therefore giving a total of 26. This results in 8 e- pairs around the As orbital; 1 being a lone pair. Maybe I'm thinking this TOTALLY wrong....

I'd greatly appreciate the help thank youu!!

fruitful - like when you bring a plan to fruition, you have set up the plan and its ready to work. a fruitful collision is one that works.
basically, kinetics and reaction rates is all about molecules colliding. for a reaction to occur a molecule must collide with the correct geometry and sufficient KE to overcome the activation energy. Thus, temperature increases number of successful collision, and enzymes help with the geometry as well as decreasing energy needed. So, in the question, since u know nothing else, you base your decision on which event will happen least often. 4 molecules colliding will happen less often than 2 molecules. thus the rate of C is slowest.

yeah, you are thinking about that completely wrong. when they say "electron pair" they mean a lone electron pair that is not involved in bonding. thus As has 1 (like u said) + 3 from each Br = 9 +1 = 10

have a fabulous night!

Answer: B Isn't this Q an error? Because As = 5 Br = 7 x 3 = 21. Therefore giving a total of 26. This results in 8 e- pairs around the As orbital; 1 being a lone pair. Maybe I'm thinking this TOTALLY wrong....

For 118. you are in the right track. But the qustion's asking the number of lone e pairs found in AsBr3, means around this whole molecule, not just the As. So, 1 from As and 3 from each Br x 3 so, total of 10, B is the right answer. Hope this helps!:)