17.1.1 Strong Acid-Strong Base and Weak Acid-Strong Base Reactions

Question 1

Strong Acid-Strong Base and Weak Acid-Strong Base Reactions

Answer 1

• Strong acids and strong bases react completely to yield a salt and water.
• The point of equilibrium for reactions involving weak acids depends heavily on the degree of acid dissociation.

Question 2

note

Answer 2

• A strong acid (such as HCl) and a strong base (such as NaOH) both dissociate completely to react and yield a salt (NaCl) and neutral water.
• Removing the spectator ions (Cl– and Na + ), the net ionic equation is the inverse of the dissociation of water.
• Remember: H 3 O + , the hydronium ion, is simply notation for a solvated proton, H + (aq)
• K eq = 1 x 10 14 (at 25 ̊C) for this reaction, so it goes completely to the right. The solution is completely neutralized.
• The point of equilibrium for reactions involving weak acids depends heavily on the degree of acid dissociation.
• For example, the equilibrium constant (K) for the reaction of acetic acid (HCOOH) and a strong base is calculated from the acid-dissociation constant (K a ) of acetic acid and the dissociation constant of water (K w ). This equilibrium constant is 1.8 x 10 10 (at 25 ̊C), indicating that the equilibrium lies far to the right. This weak acid reacts essentially completely with the strong base.

Question 3

The equilibrium constant for the autoionization of water, Kw, is equal to 1.0*10^-14. 2H2O(l) <==> H3O+(aq) + OH-(aq). What is the value of the equilibrium constant, K, for the opposite reaction? H3O+(aq) + OH-(aq) <==> 2H2O(l)

Answer 3

K = 1 / (Kw )

Question 4

The terms strong and weak are used to describe acids or bases in chemical reactions. Which statement about acids or bases is not correct?

Answer 4

Weak acids solutions become strong acid solutions at high concentration.

Question 5

Suppose that the equilibrium constant for the following reaction is 1*10^-14.
H3O+(aq) + OH-(aq) <==> 2H2O(l)
Which of the following statements about this reaction is not true?

Answer 5

Partial neutralization of the ions will occur in this reaction.

Question 6

Examine the following reaction of a weak acid and a strong base. It is easy to show that the products of the reaction are strongly favored.
Ka(formic acid) = 1.8*10^-4
HCOOH(aq) + NaOH(aq) <==> Na(HCOO)(aq) + H2O(l)
Calculate the pH of the solution at the point of exact neutralization

Answer 6

not enough information

Question 7

When hydrochloric acid interacts with sodium hydroxide to form water and sodium chloride, there are several spectator ions involved that “go along for the ride”. HCl(aq) + NaOH(aq) <==> H2O(l) + NaCl(aq)
This is more obvious in the intermediate reaction:
H3O+(aq) + Cl-(aq) + Na+(aq) + OH-(aq) <==> 2H2O(l) = Na+(aq) + Cl-(aq).
Which of the following correctly lists all of the spectator ions

Answer 7

Cl − and Na+

Question 8

Which of the following is the best definition of a neutralization reaction?

Answer 8

a reaction in which an acid and a base react to yield a salt and water

Question 9

Which statement about either acids or bases is not true?

Answer 9

Bases react with compounds containing hydroxide ions to form water and a salt.

Question 10

Suppose you begin with 100 mL each of 0.10 M acetic acid and 0.1 M sodium hydrogen sulfate and 0.10 M hydrochloric acid. If you add to each of these solutions 0.005 moles of sodium hydroxide, which one of the resulting solutions will have the lowest pH?

Answer 10

hydrochloric acid

Question 11

The reaction of hydrochloric acid and sodium hydroxide to form water and sodium chloride involves the following key reaction:
H3O+(aq) + OH-(aq) <==> 2H2O(l)
Which statement about this reaction is not correct?

Answer 11

The value of the equilibrium constant for this reaction is the same as the value for the equilibrium constant for the autoionization reaction for water.

Question 12

Calculate the equilibrium constant for the reaction below given that Ka for sulfurous acid is 1.5 × 10−2.
H2SO3(aq) + OH-(aq) <==> H2O(l) + HSO3-(aq)

Answer 12

1.5 × 10^12