Chem 280 Final Fully Solved Test Paper Graded A+

CHEM 280 FINAL FULLY SOLVED TEST PAPER
GRADED A+

◉ Bases: Properties & Examples.
Answer: -have a bitter taste
=probably due to alkaloids in organic bases found in plants


-slippery feel


-red litmus paper turns blue


◉ Arrhenius Definition of Acids.
Answer: Produces H+ (which bond to water molecules)


◉ Hydronium ion.
Answer: In water, H⁺ ions *always* associate with H₂O molecules


Chemist often use H⁺ (aq) and H₃O⁺ interchangeably to refer to this
ion


◉ Arrhenius Definition of Bases.

,Answer: produces OH⁻ ions in aqueous solution


◉ Bronsted-Lowry Definition of Acids.
Answer: an acid is a proton *donor*


◉ Bronsted-Lowry Definition of Bases.
Answer: a base is a proton *acceptor*


◉ Bronsted-Lowry Defintion of Acids/Bases (Example).
Answer: *NH₃(aq)*+H₂O↔*NH₄⁺*+OH⁻(aq)
base→conjugate acid




NH₃(aq)+*H₂O*↔NH₄⁺+*OH⁻*(aq)
acid→ conjugate base


◉ Amphoteric.
Answer: substances that can act as acids and bases


-water H₂O
-NH₃ & NH₄⁺

, ◉ Conjugated acid-base pair.
Answer: NH₃ & NH₄⁺ are often referred as this and are related to
each other by the transfer of a proton


*NH₃(aq)*+H₂O↔*NH₄⁺*+OH⁻(aq)
base→conjugate acid




NH₃(aq)+*H₂O*↔NH₄⁺+*OH⁻*(aq)
acid→ conjugate base


◉ Bronsted-Lowery (Base to).
Answer: *NH₃*+H₂O↔*NH₄⁺*+OH⁻
base→conjugate acid


NH₄⁺+*OH⁻*↔NH₃+*H₂O*
base→conjugated acid


◉ Bronsted-Lowery (Acid to).
Answer: NH₃+*H₂O*↔NH₄⁺+*OH⁻*
acid→ conjugate base