thetmoez57
Answered

Welcome to Westonci.ca, where you can find answers to all your questions from a community of experienced professionals. Our platform provides a seamless experience for finding reliable answers from a network of experienced professionals. Get precise and detailed answers to your questions from a knowledgeable community of experts on our Q&A platform.

Select the reaction that involves oxidation and reduction.

(i) [tex]NH_3 (s) + H_2O (l) \rightarrow NH_4^+ (aq) + OH^- (aq)[/tex]

(ii) [tex]2 H_2O_2 (l) \rightarrow 2 H_2O (l) + O_2 (g)[/tex]

(iii) [tex]Ba^{2+} (aq) + SO_4^{2-} (aq) \rightarrow BaSO_4 (s)[/tex]

Sagot :

GinnyAnswer
Certainly! Let's analyze each of the given reactions to determine which one involves both oxidation and reduction.

(i) [tex]\( NH_3 (s) + H_2O (l) \rightarrow NH_4^+ (aq) + OH^- (aq) \)[/tex]

In this reaction, ammonia [tex]\( NH_3 \)[/tex] reacts with water to form ammonium ion [tex]\( NH_4^+ \)[/tex] and hydroxide ion [tex]\( OH^- \)[/tex]. In this process:

- [tex]\( NH_3 \)[/tex] gains a proton (H+) from water to form [tex]\( NH_4^+ \)[/tex].
- The water molecule loses a proton to form [tex]\( OH^- \)[/tex].

This is an acid-base reaction. No oxidation or reduction (transfer of electrons) is occurring in this reaction.

(ii) [tex]\( 2 H_2O_2 (l) \rightarrow 2 H_2O (l) + O_2 (g) \)[/tex]

For this reaction, consider the oxidation states:

- In [tex]\( H_2O_2 \)[/tex] (hydrogen peroxide), each hydrogen has an oxidation state of +1. Since the compound is neutral, total oxidation state of oxygen must be -2. With two oxygens, each oxygen has an oxidation state of -1.
- In [tex]\( H_2O \)[/tex] (water), hydrogen remains +1, but with two hydrogens, total oxidation state of oxygen must be -2. Thus, each oxygen in water has an oxidation state of -2.
- In [tex]\( O_2 \)[/tex] (oxygen gas), the oxygen molecule is in its elemental form, so each oxygen atom has an oxidation state of 0.

Here, the oxygen in [tex]\( H_2O_2 \)[/tex] changes from an oxidation state of -1 to -2 in [tex]\( H_2O \)[/tex] (reduction) and from -1 to 0 in [tex]\( O_2 \)[/tex] (oxidation). Thus, both oxidation and reduction are occurring simultaneously.

(iii) [tex]\( Ba^{2+} (aq) + SO_4^{2-} (aq) \rightarrow BaSO_4 (s) \)[/tex]

This reaction is a precipitation reaction where [tex]\( Ba^{2+} \)[/tex] and [tex]\( SO_4^{2-} \)[/tex] ions combine to form solid [tex]\( BaSO_4 \)[/tex]. Both [tex]\( Ba \)[/tex] and [tex]\( SO_4 \)[/tex] retain their oxidation states before and after the reaction (+2 for [tex]\( Ba \)[/tex] and -2 for [tex]\( SO_4 \)[/tex]). Hence, no change in oxidation states occurs. This is not a redox reaction.

Among the given options, the reaction [tex]\( 2 H_2O_2 \rightarrow 2 H_2O + O_2 \)[/tex] (ii) is the one where both oxidation and reduction occur.

Therefore, the correct answer is:
_(ii) [tex]\( 2 H_2O_2 (l) \rightarrow 2 H_2O (l) + O_2 (g) \)[/tex]_
Thanks for using our service. We aim to provide the most accurate answers for all your queries. Visit us again for more insights. We appreciate your time. Please come back anytime for the latest information and answers to your questions. Stay curious and keep coming back to Westonci.ca for answers to all your burning questions.