Which of the following shows a Bronsted-Lowry acid reacting?
A. [tex]$CO + NO _2 \rightarrow CO _2+ NO$[/tex]
B. [tex]$NH _3+ H ^{+} \rightarrow NH _4{ }^{+}$[/tex]
C. [tex]$CO _3^{2-}+ H ^{+} \rightarrow HCO _3^{-}$[/tex]
D. [tex]$HCl + H _2 O \rightarrow H _3 O ^{+}+ Cl ^{-}$[/tex]
Answer (2)
A Bronsted-Lowry acid donates a proton.
Examine each reaction for proton donation.
H Cl donates a proton to H 2 O in the reaction H Cl + H 2 O → H 3 O + + C l − .
The reaction showing a Bronsted-Lowry acid reacting is H Cl + H 2 O → H 3 O + + C l − .
Explanation
Understanding Bronsted-Lowry Acids A Bronsted-Lowry acid is a substance that donates a proton (H+) in a chemical reaction. We need to identify which of the given reactions shows a species donating a proton.
Analyzing the Reactions Let's examine each reaction:
CO + N O 2 → C O 2 + NO : In this reaction, there is no proton transfer.
N H 3 + H + → N H 4 + : In this reaction, H + is reacting with N H 3 . Here, H + is the acid, but the question asks for a Bronsted-Lowry acid reacting, not being reacted upon.
C O 3 2 − + H + → H C O 3 − : In this reaction, H + is reacting with C O 3 2 − . Again, H + is the acid, but it's being reacted upon.
H Cl + H 2 O → H 3 O + + C l − : In this reaction, H Cl is donating a proton to H 2 O to form H 3 O + . Therefore, H Cl is acting as a Bronsted-Lowry acid.
Identifying the Correct Reaction Based on the analysis, the reaction where a Bronsted-Lowry acid is reacting is:
H Cl + H 2 O → H 3 O + + C l −
Final Answer The reaction that shows a Bronsted-Lowry acid reacting is H Cl + H 2 O → H 3 O + + C l − .
Examples
Bronsted-Lowry acids are crucial in many chemical processes, including acid rain formation. For instance, sulfur dioxide ( S O 2 ) released from burning fossil fuels can react with water in the atmosphere to form sulfuric acid ( H 2 S O 4 ), a Bronsted-Lowry acid. This acid then falls as acid rain, which can damage ecosystems and infrastructure. Understanding Bronsted-Lowry acid-base chemistry helps us predict and mitigate such environmental impacts.
The reaction demonstrating a Bronsted-Lowry acid in action is H Cl + H 2 O → H 3 O + + C l − . In this reaction, hydrochloric acid ( H Cl ) donates a proton to water ( H 2 O ). Therefore, H Cl acts as a Bronsted-Lowry acid.
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