i need help on both

and also this one

A solution contains a hydroxide ion concentration [OH] of 1mM. What is the pH of this solution? (numerical answer only) Question 5 2 pts A solution of lactic acid ( pKa=3.86 ) has a pH of 2.7. Which of the statements below are correct? Lactic acid is present in a higher concentration Lactic acid and lactate and present in equal concentrations Lactate is present in a higher concentration Rank the following non-covalent interactions by their average overall strength, from strongest to weakest: (a) Van der Waals interactions (b) Electrostatic (ionic) interactions (c) Hydrophobic effect (d) Hydrogen bonding Strongest 2nd strongest 2nd weakest Weakest