Water

Question 1

pH

Answer 1

percentage hydrogen ion concentration
-log10[H+]
small percentage of water molecules spontaneously dissociate (ionize) into hydroxide (OH-) ions and hydrogen (H+) ions

Question 2

what does 1 mole equal

Answer 2

6.02 x 10^23 particles of that substance

Question 2

do hydrogen ions exist in free state

Answer 2

no, they are transferred directly to a neighboring water molecule to form hydronium ions (H3O+)

Question 3

pH of pure water

Answer 3

7.0. neutral pH

Question 3

what are solutions classified as

Answer 3

acidic or basic based on their hydrogen ion concentration relative to pure water.
acidic solutions have higher [H+] than water.
basic (alkaline) solutions have lower [H+] than water

Question 4

what happens when a base is added to an aqueous solution

Answer 4

decrease [H+] by binding H+.
contains lone pair of electrons that can accept a H+

Question 4

what happens when an acid is added to an aqueous solution

Answer 4

increases [H+] by donating H+.
liberated H+ combines with a water molecule (H2O) to give a hydronium ion (H3O+)