Answer:
![\frac{[magenta\ phenolphthalein]}{[colorless\ phenolphthalein]}=31.62](https://tex.z-dn.net/?f=%5Cfrac%7B%5Bmagenta%5C%20phenolphthalein%5D%7D%7B%5Bcolorless%5C%20phenolphthalein%5D%7D%3D31.62)
Explanation:
Considering the Henderson- Hasselbalch equation for the calculation of the pH of the buffer solution as:
Where Ka is the dissociation constant of the acid.
pKa of phenolphthalein = 9.40
pH = 10.9
So,
![\frac{[magenta\ phenolphthalein]}{[colorless\ phenolphthalein]}=31.62](https://tex.z-dn.net/?f=%5Cfrac%7B%5Bmagenta%5C%20phenolphthalein%5D%7D%7B%5Bcolorless%5C%20phenolphthalein%5D%7D%3D31.62)
Answer:
refer the above attachment
Based on the information I would assume B, 73 degrees...
It shouldn't be A, 4 minutes on the burner should increase the temperature.
If it were D, it would be beyond boiling, and water takes a decent amount of energy to heat, D should be all vapor.
Same logic for C, it's basically almost boiling.
I would say 73 degrees seems most reasonable for 4 minutes.
Answer:
<h2>6.64 moles</h2>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula
![n = \frac{N}{L} \\](https://tex.z-dn.net/?f=n%20%3D%20%20%5Cfrac%7BN%7D%7BL%7D%20%5C%5C)
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
![n = \frac{4 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 6.644518...](https://tex.z-dn.net/?f=n%20%3D%20%20%5Cfrac%7B4%20%5Ctimes%20%20%7B10%7D%5E%7B24%7D%20%7D%7B6.02%20%5Ctimes%20%20%7B10%7D%5E%7B23%7D%20%7D%20%20%20%5C%5C%20%20%3D%206.644518...)
We have the final answer as
<h3>6.64 moles</h3>
Hope this helps you