What is the definition of an equivalence point in an acid-base titration?

How many moles of CH₃COOH (acetic acid) are required to neutralise 0.78 moles of NaOH (sodium hydroxide)?

(If you are struggling with some of the maths in Chemistry there is a lot of help. See the maths hub on Moodle and talk to you TA or unit coordinator to find support.) 

How many moles of NaOH (sodium hydroxide) are required to neutralise 0.36 moles of HCl (hydrochloric acid)? 

(If you are struggling with some of the maths in Chemistry there is a lot of help. See the maths hub on Moodle and talk to you TA or unit coordinator to find support.)

An aqueous solution has a hydronium ion (H₃O⁺) concentration of 6.54x10^-6 M. What is the pH of this solution? Quote your answer to three significant figures. 

(If you are struggling with some of the maths in Chemistry there is a lot of help. See the maths hub on Moodle and talk to you TA or unit coordinator to find support.)

Formic acid is the simplest carboxylic acid, HCOOH. It is the cause of pain in bee and ant stings and nearly a million tonnes are made each year because it is a good preservative. In water, formic acid behaves as a weak acid:

HCOOH_(aq) + H₂O_(l)  ⇌  HCOO^-_(aq) + H₃O⁺_(aq)

The concentration of formate ions (HCOO^-) is increased by adding sodium formate (HCOONa). Which of the statements below is the best explanation of the process of returning to equilibrium after the sodium formate has been added?

Entropy is a measure of:

Enter your answer in J·mol^-1·K^-1 to one decimal place. Do not enter units.

A spontaneous reaction is always exothermic.