Question

1. how does an indicator provide information about the ph of a solution?

a. by reacting with acids or bases in solution and forming a colored complex
b. by dissociating into ions that have a different color than the molecular form
c. by reducing the number of free hydronium or hydroxide ions in solution
d. by causing the acid or base in solution to dissociate into a colored form

1. what are the brønsted-lowry acids in the following equilibrium reaction?

\\(\text{cn}^- + \text{h}_2\text{o} \
ightleftharpoons \text{hcn} + \text{oh}^-\\)
a. \\(\text{cn}^-, \text{h}_2\text{o}\\)
b. \\(\text{h}_2\text{o}, \text{hcn}\\)
c. \\(\text{cn}^-, \text{oh}^-\\)
d. \\(\text{h}_2\text{o}, \text{oh}^-\\)

1. which of the following represents a brønsted-lowry conjugate acid-base pair?

a. \\(\text{so}_3^{2-}\\) and \\(\text{so}_2\\)
b. \\(\text{co}_3^{2-}\\) and \\(\text{co}\\)
c. \\(\text{h}_3\text{o}\\) and \\(\text{h}_2\\)
d. \\(\text{nh}_4^+\\) and \\(\text{nh}_3\\)

1. the products of self-ionization of water are ______.

a. \\(\text{h}_3\text{o}^+\\) and \\(\text{h}_2\text{o}\\)
b. \\(\text{oh}_2^-\\) and \\(\text{oh}_2^+\\)
c. \\(\text{oh}^+\\) and \\(\text{h}^-\\)
d. \\(\text{oh}^-\\) and \\(\text{h}_3\text{o}^+\\)

1. in a neutral solution, \\(\text{h}^+\\) is ______.

a. \\(10^{-14} m\\)
b. zero
c. \\(1 \times 10^7 m\\)
d. equal to \\(\text{oh}^-\\)

1. which type of solution is one with a ph of 8?

a. acidic
b. basic
c. neutral
d. the type varies, depending on the solution.

1. what characterizes a strong acid or base?

a. polar covalent bonding
b. complete ionization in water
c. ionic bonding
d. presence of a hydroxide or hydrogen ion

Answer:

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<reasoning>

Analyze indicator behavior

An acid-base indicator is a weak acid or weak base that dissociates in water. The molecular form (\(\text{HIn}\)) and its conjugate base form (\(\text{In}^-\)) have different colors. The equilibrium is represented as:
\[\text{HIn}
ightleftharpoons \text{H}^+ + \text{In}^-\]
As the pH changes, the ratio of these two colored forms shifts, changing the solution's color. Thus, it provides information by dissociating into ions that have a different color than the molecular form.

Identify Brønsted-Lowry acids

According to the Brønsted-Lowry theory, an acid is a proton (\(\text{H}^+\)) donor. In the reaction:
\[\text{CN}^- + \text{H}_2\text{O}
ightleftharpoons \text{HCN} + \text{OH}^-\]

• In the forward direction, \(\text{H}_2\text{O}\) donates a proton to \(\text{CN}^-\), making \(\text{H}_2\text{O}\) the acid.
• In the reverse direction, \(\text{HCN}\) donates a proton to \(\text{OH}^-\), making \(\text{HCN}\) the acid.

Therefore, the Brønsted-Lowry acids are \(\text{H}_2\text{O}\) and \(\text{HCN}\).

Determine conjugate acid-base pairs

A conjugate acid-base pair consists of two substances that differ only by the presence or absence of a single proton (\(\text{H}^+\)).

• \(\text{NH}_4^+\) (acid) can donate a proton to become \(\text{NH}_3\) (base).
• They differ by exactly one proton: \(\text{NH}_4^+

ightleftharpoons \text{NH}_3 + \text{H}^+\).
Thus, \(\text{NH}_4^+\) and \(\text{NH}_3\) represent a conjugate acid-base pair.

Identify self-ionization products of water

The self-ionization of water involves two water molecules reacting to form ions:
\[\text{H}_2\text{O} + \text{H}_2\text{O}
ightleftharpoons \text{H}_3\text{O}^+ + \text{OH}^-\]
The products are the hydronium ion (\(\text{H}_3\text{O}^+\)) and the hydroxide ion (\(\text{OH}^-\)).

Define neutral solution characteristics

In any aqueous solution, neutrality is defined by the balance of hydronium and hydroxide ions.

• A solution is neutral when the concentration of hydrogen ions is equal to the concentration of hydroxide ions: \([\text{H}^+] = [\text{OH}^-]\).
• At \(25^\circ\text{C}\), this concentration is \(1.0 \times 10^{-7}\text{ M}\), but the fundamental definition of neutrality at any temperature is \([\text{H}^+] = [\text{OH}^-]\).

Classify pH of 8

The pH scale at \(25^\circ\text{C}\) ranges from 0 to 14:

• \(\text{pH} < 7\) is acidic.
• \(\text{pH} = 7\) is neutral.
• \(\text{pH} > 7\) is basic.

A solution with a pH of 8 is greater than 7, which makes it basic.

Characterize strong acids and bases

By definition, strong acids and strong bases are electrolytes that ionize or dissociate completely (or nearly \(100\%\)) in aqueous solutions to produce ions. Weak acids and bases only partially dissociate.
</reasoning>

<answer>

Question 104

<mcq-option>a. by reacting with acids or bases in solution and forming a colored complex</mcq-option>
<mcq-correct>b. by dissociating into ions that have a different color than the molecular form</mcq-correct>
<mcq-option>c. by reducing the number of free hydronium or hydroxide ions in solution</mcq-option>
<mcq-option>d. by causing the acid or base in solution to dissociate into a colored form</mcq-option>

Question 105

<mcq-option>a. \(\text{CN}^-\), \(\text{H}_2\text{O}\)</mcq-option>
<mcq-correct>b. \(\text{H}_2\text{O}\), \(\text{HCN}\)</mcq-correct>
<mcq-option>c. \(\text{CN}^-\), \(\text{OH}^-\)</mcq-option>
<mcq-option>d. \(\text{H}_2\text{O}\), \(\text{OH}^-\)</mcq-option>

Question 106

<mcq-option>a. \(\text{SO}_3^{2-}\) and \(\text{SO}_2\)</mcq-option>
<mcq-option>b. \(\text{CO}_3^{2-}\) and \(\text{CO}\)</mcq-option>
<mcq-option>c. \(\text{H}_3\text{O}\) and \(\text{H}_2\)</mcq-option>
<mcq-correct>d. \(\text{NH}_4^+\) and \(\text{NH}_3\)</mcq-correct>

Question 107

<mcq-option>a. \(\text{H}_3\text{O}^+\) and \(\text{H}_2\text{O}\)</mcq-option>
<mcq-option>b. \(\text{OH}_3^-\) and \(\text{OH}_2^+\)</mcq-option>
<mcq-option>c. \(\text{OH}^+\) and \(\text{H}^-\)</mcq-option>
<mcq-correct>d. \(\text{OH}^-\) and \(\text{H}_3\text{O}^+\)</mcq-correct>

Question 108

<mcq-option>a. \(10^{-14}\text{ M}\)</mcq-option>
<mcq-option>b. zero</mcq-option>
<mcq-option>c. \(1 \times 10^7\text{ M}\)</mcq-option>
<mcq-correct>d. equal to \([\text{OH}^-]\)</mcq-correct>

Question 109

<mcq-option>a. acidic</mcq-option>
<mcq-correct>b. basic</mcq-correct>
<mcq-option>c. neutral</mcq-option>
<mcq-option>d. The type varies, depending on the solution.</mcq-option>

Question 110

<mcq-option>a. polar covalent bonding</mcq-option>
<mcq-correct>b. complete ionization in water</mcq-correct>
<mcq-option>c. ionic bonding</mcq-option>
<mcq-option>d. presence of a hydroxide or hydrogen ion</mcq-option>
</answer>

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