Answer:
The pH at the equivalence point is 7.0.
Explanation:
This is because the solution only contains water and a salt that is neutral.
Since neither H+ or OH-, molecules remain in the solution.
We can conclude that the equivalence point is 7.0.
Answer: It will take 11.775 seconds.
Explanation: As a sphere with a diameter of 0.1 mm, the area of an alveolus is
A = 4.π.r²
r for an alveolus would be: r = 0.00005m or r = 5.
m
Finding the area:
A = 4.3.14.(5.
)²
A = 3.14.
m²
The concentration change is to be 90% of the final, so
c = 0.9.3.14.
c = 28.26.
The oxygen diffusivity is 2.4.
m²/s, that means in 1 second 2.4.
of oxygen spread in one alveolus area. So:
1 second = 2.4.
m²
t seconds = 28.26.
m²
t = 
t = 11.775s
For a concentration change at the center to be 90%, it will take 11.775s.
The solution would be like
this for this specific problem:
<span><span>
E</span>=</span><span>mc</span>ΔT<span> <span>
= (</span>15<span> g</span><span>)(</span>1.91<span> <span>J<span><span>g∘</span>C</span></span>)(</span>25<span><span> ∘</span>C</span>−15<span><span> ∘</span>C</span><span>)
</span></span>= 28.65 * 10
= 286.5
<span>
I hope this helps and if you have any further questions, please don’t hesitate
to ask again. </span>
Answer:
by the VSEPR theory.
Explanation:
This question is asking for the bond angle of the
bond in
. The VSEPR (valence shell electron pair repulsion) theory could help. Start by considering: how many electron domains are there on the carbon atom between these two bond?
Note that "electron domains" refer to covalent bonds and lone pairs collectively.
- Each nonbonding pair (lone pair) of valence electrons counts as one electron domain.
- Each covalent bond (single bond, double bond, or triple bond) counts as exactly one electron domain.
For example, in
, the carbon atom at the center of that
bond has two electron domains:
- This carbon atom has two double bonds: one
bond and one
bond. Even though these are both double bonds, in VSEPR theory, each of them count only as one electron domain. - Keep in mind that there are only four valence electrons in each carbon atom. It can be shown that all four valence electrons of this carbon atom are involved in bonding (two in each of the two double bonds.) Hence, there would be no nonbonding pair around this atom.
In VSEPR theory, electron domains around an atom repel each other. As a result, they would spread out (in three dimensions) as far away from each other as possible. When there are only two electron domains around an atom, the two electron domains would form a straight line- with one domain on each side of the central atom. (To visualize, consider the three atoms in this
bond as three spheres on a stick. The central
atom would be between the other
atom and the
atom.)
This linear geometry corresponds to a bond angle of
.