Answer: 
Explanation:
Benzene is an example for six membered aromatic hydrocarbons
 
        
                    
             
        
        
        
Radio active decay reactions follow first order rate kinetics.
a) The half life and decay constant for radio active decay reactions are related by the equation:



Where k is the decay constant
b) Finding out the decay constant for the decay of C-14 isotope:



c) Finding the age of the sample :
35 % of the radiocarbon is present currently.
The first order rate equation is,
![[A] = [A_{0}]e^{-kt}](https://tex.z-dn.net/?f=%20%5BA%5D%20%3D%20%5BA_%7B0%7D%5De%5E%7B-kt%7D%20%20%20)
![\frac{[A]}{[A_{0}]} = e^{-kt}](https://tex.z-dn.net/?f=%20%5Cfrac%7B%5BA%5D%7D%7B%5BA_%7B0%7D%5D%7D%20%3D%20e%5E%7B-kt%7D%20%20)


t = 7923 years
Therefore, age of the sample is 7923 years.
 
        
             
        
        
        
The atomic mass of an element on the periodic table is the weight of 1 mole of atoms. For example, the atomic mass of Fe is 55.8 on the periodic table. If you weigh out 55.8 grams of Fe you will have 1 mole of iron, or 6.02 x 1023 atoms.
 
        
        
        
<span>The molar mass of the compound is 122 g. </span>
        
                    
             
        
        
        
Iodic acid partially dissociates into H+ and IO3- 
Assuming that x is the concentration of H+ at equilibrium, and sine the equation says the same amount of IO3- will  be released as that of H+, its concentration is also X.  The formation of H+ and IO3- results from the loss of HIO3 so its concentration at equilibrium is 0.20 M - x
Ka = [H+] [IO3-] / [HIO3]; 
<span>Initially, [H+] ≈ [IO3-] = 0 and [HIO3] = 0.20; </span>
<span>At equilibrium [H+] ≈ [IO3-] = x and [HIO3] = 0.20 - x; </span>
<span>so 0.17 = x² / (0.20 - x); </span>
<span>Solving for x using the quadratic formula: </span>
<span>x = [H+] = 0.063 M or pH = - log [H+] = 1.2.</span>