Which of the following statements is correct for the activation energy of a reaction?

The variation of the rate constant with temperature is given by the Arrhenius equation $k = A e^{-E_a / (RT)}$. If $T \to \infty$,the rate constant $k$ will be equal to:

An egg takes $4.0 \text{ minutes}$ to boil at sea level where the boiling point of water is $T_1 \text{ K}$, whereas it takes $8.0 \text{ minutes}$ to boil on a mountain top where the boiling point of water is $T_2 \text{ K}$. The activation energy for the reaction that takes place during the boiling of an egg is:

What names apply to chemical species corresponding to locations $1$ and $2$ on this reaction coordinate diagram?
Location $1$ $-$ Location $2$

For the reaction $A_2 + B_2 \rightleftarrows 2AB$,the activation energy for the forward and backward reactions are $180 \ kJ \ mol^{-1}$ and $200 \ kJ \ mol^{-1}$,respectively. If a catalyst lowers the activation energy of both forward and backward reactions by $100 \ kJ \ mol^{-1}$,what will be the enthalpy change $(\Delta H)$ for the reaction $A_2 + B_2 \rightarrow 2AB$ in the presence of the catalyst?

It is found that for every $10^{\circ}C$ rise in temperature,the rate of the reaction doubles itself. This is mainly because