Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 16: Problem 90

Based on their compositions and structures and on conjugate acid-base relationships, select the stronger base in each of the following pairs: (a) \(\mathrm{NO}_{3}^{-}\) or \(\mathrm{NO}_{2}^{-},\) (b) \(\mathrm{PO}_{4}^{3-}\) or \(\mathrm{AsO}_{4}^{3-}\), (c) \(\mathrm{HCO}_{3}^{-}\) or \(\mathrm{CO}_{3}^{2-}\).

Short Answer

Expert verified
The stronger bases in each pair are: (a) \(\mathrm{NO}_{2}^{-}\), (b) \(\mathrm{AsO}_{4}^{3-}\), and (c) \(\mathrm{CO}_{3}^{2-}\).

Step by step solution

01

Pair (a): Compare \(\mathrm{NO}_{3}^{-}\) and \(\mathrm{NO}_{2}^{-}\)

To determine the stronger base between \(\mathrm{NO}_{3}^{-}\) and \(\mathrm{NO}_{2}^{-}\), we can look at their conjugate acids: \(\mathrm{HNO}_3\) (nitric acid) and \(\mathrm{HNO}_2\) (nitrous acid). Remember that the stronger the conjugate acid is, the weaker its corresponding base will be. Nitric acid (\(\mathrm{HNO}_3\)) is a strong acid, so its conjugate base, \(\mathrm{NO}_{3}^{-}\), will be a weak base. On the other hand, nitrous acid (\(\mathrm{HNO}_2\)) is a weak acid, so its conjugate base, \(\mathrm{NO}_{2}^{-}\), will be a stronger base. So, the stronger base in this pair is \(\mathrm{NO}_{2}^{-}\).
02

Pair (b): Compare \(\mathrm{PO}_{4}^{3-}\) and \(\mathrm{AsO}_{4}^{3-}\)

To determine the stronger base between \(\mathrm{PO}_{4}^{3-}\) and \(\mathrm{AsO}_{4}^{3-}\), we can again look at their conjugate acids: \(\mathrm{H}_{3}\mathrm{PO}_{4}\) (phosphoric acid) and \(\mathrm{H}_{3}\mathrm{AsO}_{4}\) (arsenic acid). Both phosphoric acid (\(\mathrm{H}_{3}\mathrm{PO}_{4}\)) and arsenic acid (\(\mathrm{H}_{3}\mathrm{AsO}_{4}\)) are weak acids. However, the \(\mathrm{As-O}\) bond in arsenic acid is weaker due to the larger atomic size of arsenic than phosphorus, which makes the conjugate base \(\mathrm{AsO}_{4}^{3-}\) more likely to accept a proton. Thus, the stronger base in this pair is \(\mathrm{AsO}_{4}^{3-}\).
03

Pair (c): Compare \(\mathrm{HCO}_{3}^{-}\) and \(\mathrm{CO}_{3}^{2-}\)

To determine the stronger base between \(\mathrm{HCO}_{3}^{-}\) and \(\mathrm{CO}_{3}^{2-}\), we can look at their conjugate acids: \(\mathrm{H}_{2}\mathrm{CO}_{3}\) (carbonic acid) and \(\mathrm{HCO}_{3}^{-}\) (hydrogen carbonate). When \(\mathrm{HCO}_{3}^{-}\) accepts a proton (H+ ion), it forms the weak acid \(\mathrm{H}_{2}\mathrm{CO}_{3}\). However, when \(\mathrm{CO}_{3}^{2-}\) accepts a proton (H+ ion), it forms \(\mathrm{HCO}_{3}^{-}\), which is a stronger acid than carbonic acid. Therefore, \(\mathrm{CO}_{3}^{2-}\) is a stronger base compared to \(\mathrm{HCO}_{3}^{-}\). Thus, the stronger base in this pair is \(\mathrm{CO}_{3}^{2-}\).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

(a) The hydrogen carbonate ion \(\left(\mathrm{HCO}_{3}^{-}\right)\) is amphiprotic. Write a balanced chemical equation showing how it acts as an acid toward water and another equation showing how it acts as a base toward water.

Calculate \(\left[\mathrm{H}^{+}\right]\) for each of the following solutions, and indicate whether the solution is acidic, basic, or neutral: (a) $\left[\mathrm{OH}^{-}\right]=7.3 \times 10^{-10} \mathrm{M}(\mathbf{b})\left[\mathrm{OH}^{-}\right]=0.015 \mathrm{M} ;$ (c) a solution in which \(\left[\mathrm{H}^{+}\right]\) is 10 times greater than \(\left[\mathrm{OH}^{-}\right]\).

An unknown salt is either $\mathrm{KBr}, \mathrm{NH}_{4} \mathrm{Cl}, \mathrm{KCN},\( or \)\mathrm{K}_{2} \mathrm{CO}_{3} .\( If a \)0.100 \mathrm{M}$ solution of the salt is neutral, what is the identity of the salt?

A \(0.100 \mathrm{M}\) solution of cyanic acid (HCNO) is \(5.9 \%\) ionized. Using this information, calculate [CNO^ \(\left.^{-}\right],\left[\mathrm{H}^{+}\right],[\mathrm{HCNO}],\) and \(K_{a}\) for cyanic acid.

Codeine \(\left(\mathrm{C}_{18} \mathrm{H}_{21} \mathrm{NO}_{3}\right)\) is a weak organic base. A \(5.0 \times 10^{-3} \mathrm{M}\) solution of codeine has a pH of 9.95. Calculate the value of \(K_{b}\) for this substance. What is the \(\mathrm{p} K_{b}\) for this base?
See all solutions

Recommended explanations on Chemistry Textbooks

Chemical Reactions

Read Explanation

Chemistry Branches

Read Explanation

Kinetics

Read Explanation

Physical Chemistry

Read Explanation

Ionic and Molecular Compounds

Read Explanation

The Earths Atmosphere

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free