Question

question 38 (0.0862 points)
considering the following precipitation reaction:
pb(no₃)₂(aq) + 2ki(aq) → pbi₂(s) + 2kno₃(aq)
which ion(s) are the spectator ions?

○ pb²⁺, no₃⁻

○ pb²⁺, k⁺

○ k⁺, no₃⁻

○ k⁺, i⁻

question 39 (0.0862 points)
which of the following statements is true about the ketone functional group?

○ it contains a double bonded oxygen on the last carbon in the carbon chain.

○ it contains a double bonded oxygen on a carbon that is also bonded to an oh
group.

○ it contains a double bonded oxygen on a carbon that is bonded to 2 other

Explanation:

Question 38

Step1: Recall Spectator Ion Definition

Spectator ions are ions that do not participate in the chemical reaction (they remain in solution unchanged). To find them, we write the complete ionic equation.
The reactants in ionic form: \( \text{Pb}^{2+}(aq) + 2\text{NO}_3^-(aq) + 2\text{K}^+(aq) + 2\text{I}^-(aq)
ightarrow \text{PbI}_2(s) + 2\text{K}^+(aq) + 2\text{NO}_3^-(aq) \)

Step2: Identify Ions Not Changing

From the ionic equation, \( \text{K}^+ \) and \( \text{NO}_3^- \) are present on both sides (reactants and products) in the same form, so they are spectator ions. \( \text{Pb}^{2+} \) and \( \text{I}^- \) form the precipitate \( \text{PbI}_2 \), so they are not spectator ions.

Step1: Recall Ketone Functional Group

A ketone has a carbonyl group (\( \text{C}=\text{O} \)) where the carbon of the carbonyl is bonded to two other carbon atoms (R - \( \text{C}(=\text{O}) \) - R, where R is an alkyl/aryl group).

• The first option describes an aldehyde (carbonyl on the terminal carbon).
• The second option describes a carboxylic acid derivative or a hydroxy - ketone (but not a typical ketone; a carbon with \( \text{C}=\text{O} \) and \( \text{OH} \) is a carboxylic acid or related, not a ketone).
• The third option (assuming) matches the ketone definition: carbonyl carbon bonded to two other carbons.

Step2: Select Correct Statement

Based on the definition of a ketone, the correct statement is the one where the carbon with the double - bonded oxygen is bonded to 2 other carbons.

Answer:

\( \text{K}^+, \text{NO}_3^- \) (the option with \( \text{K}^+, \text{NO}_3^- \))

Question 39 (assuming the third option is "It contains a double bonded oxygen on a carbon that is bonded to 2 other carbons" as the typical ketone definition)