1. Not visible clearly
2. First Compound has pka 12.8 since it is more acidic. Since it has strong withdrawing group CCl3 which increases the acidity while second has more pka 19, less acidic.
3. Given product is an ether, it should be prepared by sn2 reaction.
Primary halide is the good reactant for SN2 reaction. hence given one is not feasible.
It gives Elimination product instead of SN2 product.