Answer:
physical change because even though gas formation was observed the water was undergoing a state change which means that it's original properties are preserved
Answer:
of HA is 6.80
Explanation:
Acid dissociation constant (
) of HA is represented as-
![K_{a}=\frac{[H^{+}][A^{-}]}{[HA]}](https://tex.z-dn.net/?f=K_%7Ba%7D%3D%5Cfrac%7B%5BH%5E%7B%2B%7D%5D%5BA%5E%7B-%7D%5D%7D%7B%5BHA%5D%7D)
Where species inside third bracket represents equilibrium concentrations
Now, plug in all the given equilibrium concentration into above equation-
So, 
Hence 
Answer:
Carbon
Explanation:
Carbon has four electrons in its valence shell, so it generally shares it in a covalent bond. This element needs four electrons to be stable, so it can form single (such as the bond with hydrogen), double (such as the bond with oxygen) or triple bonds (such as the bond with nitrogen).
It can also form bonds with other carbon, and they can form longs chains, that's why there are a lot of organic compounds (the compounds with carbon). Carbon can form rings too, such as in benzene.
You first add the manganese and exchange the number of electrons needed with the hydroxide. While the hydroxide needs only 1 electron the manganese needs 4, so after you exchange the electrons the manganese will be just 1 atom while the hydroxide is 4. Mn(OH)4
