General, Organic, and Biochemistry - Chapter 8: Acids and Bases and Oxidation-Reduction Reactions

Comprehensive practice questions covering acid-base theories, pH calculations, titration, buffers, and oxidation-reduction reactions.

According to the Arrhenius theory, how is an acid defined?

A substance that, when dissolved in water, dissociates to produce hydrogen ions ($H^+$).

What is the Arrhenius definition of a base?

A substance that, when dissolved in water, dissociates to produce hydroxide ions ($OH^-$).

How does the Brønsted-Lowry theory define an acid and a base?

An acid is a proton ($H^+$) donor and a base is a proton ($H^+$) acceptor.

What term describes a substance, like water, that possesses both acid and base properties?

Amphiprotic

What is a conjugate acid?

What the base becomes after it accepts a proton.

What is a conjugate base?

What the acid becomes after it donates its proton.

Which six acids are listed as strong acids in the transcript?

Hydrochloric Acid ($HCl$), Hydrobromic Acid ($HBr$), Hydroiodic Acid ($HI$), Nitric Acid ($HNO_3$), Sulfuric Acid ($H_2SO_4$), and Perchloric Acid ($HClO_4$).

What is the definition of a weak acid or base in terms of dissociation?

A substance where only a small percent dissociates (weak electrolytes).

What is the ion product constant for water ($K_w$) at room temperature?

$$K_w = [H_3O^+][OH^-] = 1.0 \times 10^{-14}$$

What is the mathematical definition of pH?

$$pH = -\log[H_3O^+]$$

What are the pH ranges for acidic, neutral, and basic solutions?

Acidic is less than $7$, neutral is exactly $7$, and basic is greater than $7$ (up to $14$).

What is a neutralization reaction?

The reaction of an acid with a base to produce a salt and water.

What is the net ionic equation for the neutralization of any strong acid with a strong base?

$$H^+(aq) + OH^-(aq) \rightarrow H_2O(l)$$

In a titration, what is the equivalence point?

The point when the moles of $H^+$ and $OH^-$ are equal.

Define a polyprotic substance.

A substance that donates or accepts more than one proton per formula unit.

What is a buffer solution?

A solution which resists large changes in pH when either acids or bases are added.

What is the Henderson-Hasselbalch Equation for the acetic acid/sodium acetate system?

$$pH = pK_a + \log\left( \frac{[\text{conjugate base}]}{[\text{weak acid}]} \right)$$

What are the physiological conditions of acidosis and alkalosis in relation to blood pH and $CO_2$?

Acidosis occurs when high $CO_2$ makes blood acidic; alkalosis occurs when low $CO_2$ (often from hyperventilation) makes blood basic.

What are the three ways to define oxidation?

Loss of electrons, loss of hydrogen atoms, or gain of oxygen atoms.

What are the three ways to define reduction?

Gain of electrons, gain of hydrogen, or loss of oxygen.

In a redox reaction, what does the oxidizing agent do?

It is reduced, gains electrons, and causes oxidation.

What is a voltaic cell?

An electrochemical cell that converts stored chemical energy into electrical energy.

In a voltaic cell, what occurs at the anode and the cathode?

Oxidation occurs at the anode and reduction occurs at the cathode.

How does electrolysis differ from a voltaic cell?

Electrolysis uses electrical energy to cause nonspontaneous oxidation-reduction reactions to occur.