I believe its the first one because manganese is mn and IV is 4 but the cross thing thing will making it the second one but then you have to simplify making it the first one i hope that helps:)
I have provided the steps and solution within the attachment. The pH of the solution would be 12.30, this indicates that the solution is basic, as a higher value of pH indicates presence of more hydroxide ions and less of hydrogen ions in the solution.
Answer:
6,41 min
Explanation:
For the reaction:
A → products
kinetics first-order reaction law is:
ln[A] = ln[A]₀ -kt
Where [A] is concentration of reactant, [A]₀ is initital concentration of reactant, k is rate constant and t is time.
If the concentration of A is 6,25% you can assume:
[A] = 6,25; [A]₀= 100. Replacing:
ln(6,25) = ln(100) -7,20×10⁻³s⁻¹t
-2,7726 = -7,20×10⁻³s⁻¹t
385s = t
In minutes:
385s×
= <em>6,41 min</em>
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I hope it helps!