Question

1. which species is a spectator ion in \\(\text{agno}_3 + \text{nacl} \

ightarrow \text{agcl} + \text{nano}_3\\)?
a. \\(\text{ag}^+\\)
b. \\(\text{cl}^-\\)
c. \\(\text{na}^+\\)
d. \\(\text{agcl}\\)

1. how many oxygen atoms are in \\(3.00\text{ mol co}_2\\)?

a. \\(3.00\text{ mol}\\)
b. \\(6.00\text{ mol}\\)
c. \\(1.81 \times 10^{24}\text{ atoms}\\)
d. both b and c

1. which statement is true about ap chemistry preparation?

a. memorization alone is enough
b. units do not matter
c. strong mole and ion skills help a lot
d. balancing equations is unnecessary

Explanation:

Identify spectator ions in the precipitation reaction

To find the spectator ions in the reaction:

$$\text{AgNO}_3(aq) + \text{NaCl}(aq) ightarrow \text{AgCl}(s) + \text{NaNO}_3(aq)$$

We write the complete ionic equation by dissociating soluble strong electrolytes:

$$\text{Ag}^+(aq) + \text{NO}_3^-(aq) + \text{Na}^+(aq) + \text{Cl}^-(aq) ightarrow \text{AgCl}(s) + \text{Na}^+(aq) + \text{NO}_3^-(aq)$$

Spectator ions appear unchanged on both sides:

• \(\text{Na}^+(aq)\)
• \(\text{NO}_3^-(aq)\)

Comparing with the given options:

• A. \(\text{Ag}^+\) (participates in forming the precipitate)
• B. \(\text{Cl}^-\) (participates in forming the precipitate)
• C. \(\text{Na}^+\) (remains in solution unchanged)
• D. \(\text{AgCl}\) (the precipitate product)

Therefore, \(\text{Na}^+\) is a spectator ion.

Calculate oxygen atoms in carbon dioxide

We are given \(3.00\text{ mol of }\text{CO}_2\).

First, calculate the moles of oxygen atoms:

$$\text{Moles of O} = 3.00\text{ mol }\text{CO}_2 \times \frac{2\text{ mol O}}{1\text{ mol }\text{CO}_2} = 6.00\text{ mol O}$$

Next, calculate the absolute number of oxygen atoms using Avogadro's number:

$$\text{Number of O atoms} = 6.00\text{ mol} \times 6.022 \times 10^{23}\text{ atoms/mol} \approx 3.61 \times 10^{24}\text{ atoms}$$

Let's evaluate the options:

• A. \(3.00\text{ mol}\) (incorrect)
• B. \(6.00\text{ mol}\) (correct representation in moles)
• C. \(1.81 \times 10^{24}\text{ atoms}\) (this is the number of \(\text{CO}_2\) molecules: \(3.00 \times 6.022 \times 10^{23} \approx 1.81 \times 10^{24}\))
• D. Both B and C (incorrect, since C is the number of molecules, not oxygen atoms)

Thus, the correct option is B.

Evaluate AP Chemistry preparation statements

Let's analyze each statement regarding AP Chemistry preparation:

• A. "Memorization alone is enough" (False, conceptual understanding and problem-solving are critical)
• B. "Units do not matter" (False, dimensional analysis and units are essential)
• C. "Strong mole and ion skills help a lot" (True, stoichiometry and aqueous chemistry are foundational)
• D. "Balancing equations is unnecessary" (False, balanced equations are required for stoichiometry)

Thus, the correct option is C.

Answer:

Question 13

• (A) Ag+
• (B) Cl-
• (C) Na+ (Correct answer)
• (D) AgCl

Question 14

• (A) 3.00 mol
• (B) 6.00 mol (Correct answer)
• (C) 1.81×10^24 atoms
• (D) Both B and C

Question 15

• (A) Memorization alone is enough
• (B) Units do not matter
• (C) Strong mole and ion skills help a lot (Correct answer)
• (D) Balancing equations is unnecessary