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:
![pH=pKa+\log\frac{[base]}{[acid]}](https://tex.z-dn.net/?f=pH%3DpKa%2B%5Clog%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D)
Where Ka is the dissociation constant of the acid.
pKa of phenolphthalein = 9.40
pH = 10.9
So,
![10.9=9.40+\log\frac{[magenta\ phenolphthalein]}{[colorless\ phenolphthalein]}](https://tex.z-dn.net/?f=10.9%3D9.40%2B%5Clog%5Cfrac%7B%5Bmagenta%5C%20phenolphthalein%5D%7D%7B%5Bcolorless%5C%20phenolphthalein%5D%7D)
Answer:
A. Both freezing and melting are physical changes.
Explanation:
Even if you were to freeze water, the molecules are still water molecules, and vise versa with melting it.
Answer:
A
Explanation:
matter has mass and undergoes a phase change
H^+(aq) + OH^-(aq) ---> H2O(l)
<span>Na^+ and ClO4^- are the spectator ions.</span>
Answer:
Cooling a substance causes molecules to slow down and get slightly closer together, occupying a smaller volume that results in an increase in density. Hot water is less dense and will float on room-temperature water. <u>Cold water is more dense and will sink in room-temperature water.</u>
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