Qualitative observation. Which is data or information with your senses such as sight, taste, smell, and touch.
To calculate the average mass of the element, we take the summation of the product of the isotope and the percent abundance. We calculate as follows:
Average atomic mass = .374 ( 184.953 amu ) + .626 ( <span>186.958 amu ) = 186.208 amu
Hope this answers the question. Have a nice day.</span>
Answer:
Choice A: approximately
.
Explanation:
Note that the unit of concentration,
, typically refers to moles per liter (that is:
.)
On the other hand, the volume of the two solutions in this question are apparently given in
, which is the same as
(that is:
.) Convert the unit of volume to liters:
.
.
Calculate the number of moles of
formula units in that
of the
solution:
.
Note that
(sulfuric acid) is a diprotic acid. When one mole of
completely dissolves in water, two moles of
ions will be released.
On the other hand,
(sodium hydroxide) is a monoprotic base. When one mole of
formula units completely dissolve in water, only one mole of
ions will be released.
ions and
ions neutralize each other at a one-to-one ratio. Therefore, when one mole of the diprotic acid
dissolves in water completely, it will take two moles of
to neutralize that two moles of
produced. On the other hand, two moles formula units of the monoprotic base
will be required to produce that two moles of
. Therefore,
and
formula units would neutralize each other at a two-to-one ratio.
.
.
Previous calculations show that
of
was produced. Calculate the number of moles of
formula units required to neutralize that
.
Calculate the concentration of a
solution that contains exactly
of
formula units:
.
Let us say that R is the major enantiomer, while
S is the minor enantiomer, therefore the formula for enantiomeric excess (ee)
is:
ee = (R – S) * 100%
Let us further say that the fraction of R is x (R
= x), and therefore fraction of S is 1 – x (S = 1 – x), therefore:
75 = (x – (1 – x)) * 100
75 = 100 x – 100 + 100 x
200 x = 175
x = 0.875
Summary of answers:
R = major enantiomer = 0.875 or 87.5%
<span>S = minor enantiomer = (1 – 0.875) = 0.125 or
12.5%</span>