Try common ratio, because b represents a constant variable. (I’m not 100% but it may be this)
Answer:
- 484 KJ/mol
Explanation:
The reaction equation is;
CH4(g) + F2 (g) ------> CH3F(g) + HF(g)
The enthalpy of the reaction can be calculated from bond energies using the formula;
ΔHreaction = Bond energy of reactants - bond energy of products
or
ΔHreaction = Bonds broken - bonds formed
[4(413) + 1(155) - 3(413) + 1(485) + 1(567)]
[(1652 + 155) - (1239 + 485 + 567)]
[1807 - 2291]
= - 484 KJ/mol
This answer is true.
If there is so much lettuce in the world that it can be had very easily in any venue, then the monetary value of the lettuce is diminished because it is so easily had.
All you have to do is to find the following from the z-score table:
On the 1st row of the table, you can read the value of z & you complete the value by reading the corresponding horizontal line. However watch out which table you are using & what is requested from you. For example in the following question:
a. Between the mean and a z = 1.27: , if you use a normal table it will give you the value of ==> 0.8990==>89.8%, which is the area from the EXTREME LEFT TO z=1.27., whereas yo have to calculate the area from the mean to
to z=1.27 0r 0.8990 -.5=0.398 or 39.85 (.5, because you start counting from the mean):
so:
a. Between the mean and a z = 1.27 ==> 39.8%
b. Between the mean and a z = -0.91 ==> 0.31859==>18.31%
c. Between the z scores of -1.84 and 1.39 . In this case you will find the value of each z & you will add up both: for z= -1.84 ==> 0.88482 or 88.48%
d. Between the z scores of -2.58 and 2.58: same as above,==>99.1%
e. Above a z of 1.96 , means from z to the end. The area from the mean to z=1.96 ==> 0.475, what wee need is from this point to the end
that is 0.5-0.475=2.5%
f. Below a z score of -2.58 same as above but -2.58 to the extreme left
for z=-2.58 ==>0.49506 , & below this area==> 0.5-0.49506==> 0.49%
g. Above a z score of -1.72 ==> 95.72%
h. Below a z of 1.96 ==>97.5%
