Ch 18 review question 1
What are the Bronsted-Lowry definitions of acid and base?
An acid donates hydrogen ions and a base accepts hydrogen ions.
When an acid is dissolved in water, what ion does the water form?
The hydrogen ion quickly bonds to a water molecule to form a hydronium ion.
When a chemical loses a hydrogen ion, is it behaving as an acid or base?
When a chemical loses a hydrogen ion, it is acting like an acid.
Why does a solution of a strong acid conduct electricity better than a solution of a weak acid with the same concentration?
A strong acid means it ionizes completely and forms a lot of ions, which conduct electricity very well. A weak acid doesn't form as many ions.
When can a solution of a weak base be more corrosive than a solution of a strong base?
When the weak base is a lot more concentrated that then strong base, it can be more corrosive.
What is true about the relative cncentrations of a hydronium and hydroxide ions in an acidic solution? How about a neutral solution? A base solution?
In an acid, the concentration of hydronium ions is more than the concentration of hydroxide ions. In a base, the hydroxide concentration is more than the hydronium concentration. In a neutral solution, the hydronium concentration equals the hydroxide concentration.
An acid and a base react to form a salt, which consists of positive and negative ions. Which forms the positive ions: the acid or the base? Which forms the negative ions?
The base accepted the hydrogen ion, H+, and thus gained a positive charge. The base thus forms the positively charged ion. Conversely, the acid donated a hydrogen ion and thys lost a positive charge. The acid thus forms the negaively charged ion.
Water is formed from the reaction between an acid and a base. Why is water not classified as a salt?
A salt is the ionic compound produced from the reaction of an acid and a base. Water is a covalent compound.
Many of the smelly molecules of cooked fish are alkaline compounds. How might these smelly molecules be conveniently transformed into less smelly salts just before eating the fish?
Squeeze lemon juice on the fish. The citric acid found in lemon juice reacts with these smelly alkaline compounds to form less smelly salts. The smell and taste of the lemon also helps to mask any additional undesirable fishy odors.
Why is the H-F bond so much stronger than the H-I bond? (Think atomic size)
As can be deduced from their relative positions in the periodic table, the fluorine atom is much smaller than the iodine atom. The atoms of the H-F bond, therefore, are closer together than are the atoms within the H-I bond. When it comes to electrical attractions, closeness wins. Thus, the H-F bond is stronger.
Which bond is easier to break, H-F or H-I?
As given in the answer to exercise 13, the H-I bond is weaker and so it is easier to break.
Which is the stronger acid: H-F or H-I?
The H-I bond is weaker and so it is easier to break. This, in turn, means that the H-I molecule more readily splits apart to form the hydrogen ion. The H-I, therefore, is a stronger acid.