Final answer:
In Chemistry, a base commonly has a hydroxide anion with a -1 charge and accepts protons or donates a pair of valence electrons. KOH is an Arrhenius base while Ni(OH)2, Al(OH)3, and AgOH are examples of compound formulas for bases.
Step-by-step explanation:
Understanding Bases in Chemistry
In Chemistry, a base is a substance that can accept protons from acids according to the Bronsted-Lowry definition or donate a pair of valence electrons to form a bond according to the Lewis definition. Bases commonly contain a hydroxide anion (OH-) which has a charge of -1. For instance, substances like KOH (potassium hydroxide) and Mg(OH)2 (magnesium hydroxide) are considered bases because they can dissociate in water to yield hydroxide ions.
Regarding Exercise 12.2.1, KOH is an Arrhenius base as it increases the concentration of OH- ions when dissolved in water. On the other hand, H2SO4 (sulfuric acid) is an Arrhenius acid, and C2H6 (ethane) is neither an acid nor a base in the Arrhenius sense.
To answer specific questions about bases:
- The formula for nickel (II) hydroxide is Ni(OH)2.
- The formula for aluminum hydroxide is Al(OH)3.
- The formula for silver hydroxide is AgOH.
- Among CH3NH2 and (CH3)2NH, the stronger base is (CH3)2NH, and the corresponding stronger conjugate acid is (CH3)2NH2+.
The Bronsted-Lowry base among the given options in Exercise 7.2.2 is HPO42- as it can accept a proton to become H2PO4-.