help please

1. Determine the velocity of a second order reaction X+Y-Z when the reaction solution contains 3 um X and 5 uM Y, and k for the reaction is 400 M. (1 point) 2. For a chemical reaction A+B C+D (under constant pressure), when the reaction temperature increases, the reaction favors the product (C+D) formation. Can you tell this is an exothermic reaction or endothermic reaction? Use appropriate thermodynamic equation and plot to justify your answer. (1 point) 3. How many mL of a 2.0 M solution of boric acid must be added to 500 mL of a solution of 10 MM sodium borate in order for the pH to be 9.55? (1 point) 4. Calculate and describe how to make 1 L potassium phosphate buffer with a molarity of 0.150 M, and pH 7.4 (2 points)