Answer:
Explanation:
Hello,
In this case, for first order reactions, we can use the following integrated rate law:
![ln(\frac{[A]}{[A]_0} )=kt](https://tex.z-dn.net/?f=ln%28%5Cfrac%7B%5BA%5D%7D%7B%5BA%5D_0%7D%20%29%3Dkt)
Thus, we compute the time as shown below:
![t=-\frac{ln(\frac{[A]}{[A]_0} )}{k}=- \frac{ln(\frac{0.220M}{0.690M} )}{0.55s^{-1}} \\\\t=-\frac{-1.14}{0.550s^{-1}}\\ \\t=2.08s](https://tex.z-dn.net/?f=t%3D-%5Cfrac%7Bln%28%5Cfrac%7B%5BA%5D%7D%7B%5BA%5D_0%7D%20%29%7D%7Bk%7D%3D-%20%5Cfrac%7Bln%28%5Cfrac%7B0.220M%7D%7B0.690M%7D%20%29%7D%7B0.55s%5E%7B-1%7D%7D%20%5C%5C%5C%5Ct%3D-%5Cfrac%7B-1.14%7D%7B0.550s%5E%7B-1%7D%7D%5C%5C%20%5C%5Ct%3D2.08s)
Best regards.
1) Answer is: 5.
Chemical dissociation of aluminium sulfide in water:
Al₂S₃(aq) → 2Al³⁺(aq) + 3S²⁻(aq).
There are five ions, two aluminium cations and three sulfide anions.
2) Answer is: 4.
Chemical dissociation of aluminium fluoride in water:
AlF₃(aq) → Al³⁺(aq) + 3F⁻(aq).
There are four ions, one aluminium cation and three fluoride anions.
Aluminium has oxidation +3, because it lost three electrons, to gain electron configuration as noble gas neon.
