Answer: The pH of an aqueous solution of .25M acetic acid is 2.7
Explanation:

cM 0 0
So dissociation constant will be:

Give c= 0.25 M and
= ?

Putting in the values we get:


![[H^+]=c\times \alpha](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3Dc%5Ctimes%20%5Calpha)
![[H^+]=0.25\times 0.0084=0.0021](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D0.25%5Ctimes%200.0084%3D0.0021)
Also ![pH=-log[H^+]](https://tex.z-dn.net/?f=pH%3D-log%5BH%5E%2B%5D)
![pH=-log[0.0021]=2.7](https://tex.z-dn.net/?f=pH%3D-log%5B0.0021%5D%3D2.7)
Thus pH is 2.7
It's B ------------------------------------
Answer:
This question is incomplete
Explanation:
This question is incomplete because the result of the described experiment would have better determined the type of scientific explanation to profer. However, the type of material that will preserve the relative hotness or temperature of the hot coffee for the longest time will be a material than can resist heat transfer. These materials tend to keep hot substances hot by not allowing the heat of the coffee to be conducted or pass through it. These materials are mostly insulators or made by placing an insulator between two heat conductors.
Generally, heat is usually transferred from a region of higher concentration to a region of lower concentration, hence when the heat is denied of this transfer, the heat will remain trapped in the "heat-donor" substance (in this case the hot coffee). Thus, the material chosen (A, B or C) will be the material that resists heat transfer the most based on the explanation above.
Because there is less friction on the marble floor.
It has more lines in it compared to hydrogen emission spectrum. It is mainly because the helium atom has more electrons than a hydrogen atom. Therefore, more electrons get excited when we pass a white light beam through a helium sample, and it causes the emission of more spectral lines