Which dicarboxylic acid in presence of a dehydrating agent is least reactive to give an anhydride?

Consider the given plots for a reaction obeying Arrhenius equation (0^oC < T < 300^oC) : (K and Ea are rate constant and activation energy, respectively)



Choose the correct option :

Which of the graphs shown below does not represent the relationship between incident light and the electron ejected from metal surface ?

The increasing order of the pKa values of the following compounds is :