/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 44 Predict whether the following sa... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 20: Problem 44

Predict whether the following salts, when dissolved in water, produce acidic, basic, or neutral solutions: (a) KCN(s) (b) \(\mathrm{Pb}\left(\mathrm{NO}_{3}\right)_{2}(s)\) (c) \(\mathrm{NaHSO}_{4}(s)\) (d) \(\mathrm{CaCl}_{2}(s)\)

Short Answer

Expert verified
(a) Basic; (b) Neutral; (c) Acidic; (d) Neutral.

Step by step solution

01

Understand the Basic Concept of Salt Hydrolysis

When a salt is dissolved in water, it dissociates into its constituent ions. These ions can interact with water to form either acidic or basic solutions depending on whether the ions originate from strong or weak acids/bases. Strong acids and bases fully dissociate in water, while weak acids and bases partially dissociate.
02

Analyze Each Salt

To predict acidity or basicity: (a) Identify ions formed from dissociation. (b) Determine their origin (strong acid/base or weak acid/base). (c) Infer the nature of the resulting solution (acidic, basic, or neutral).
03

Analyze KCN(s)

Dissociates into K鈦� and CN鈦�. K鈦� comes from a strong base (KOH) and does not affect pH. CN鈦� comes from a weak acid (HCN) and tends to create a basic solution as it reacts with water to form OH鈦�.
04

Analyze Pb(NO鈧�)鈧�(s)

Dissociates into Pb虏鈦� and NO鈧冣伝. NO鈧冣伝 comes from a strong acid (HNO鈧�) and does not affect pH. Pb虏鈦� is less likely to hydrolyze significantly in water, leading to a neutral solution overall.
05

Analyze NaHSO鈧�(s)

Dissociates into Na鈦� and HSO鈧勨伝. Na鈦� comes from a strong base (NaOH) and does not affect pH. HSO鈧勨伝 can donate a proton (H鈦�), making the solution acidic.
06

Analyze CaCl鈧�(s)

Dissociates into Ca虏鈦� and Cl鈦�. Both ions come from strong counterparts (Ca(OH)鈧� is a strong base and HCl is a strong acid), leading to no alteration of the water's pH, resulting in a neutral solution.

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.

Over 30 million students worldwide already upgrade their learning with 91影视!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Salt Hydrolysis
Salt hydrolysis happens when a salt is dissolved in water, splitting into its component ions. These ions can interact with water molecules in a process called hydrolysis, altering the pH of the solution. This interaction largely depends on the strength of the acids and bases from which the ions originate.
For example, if a salt derives from a strong base and a weak acid, the anion from the weak acid is likely to react with water to produce hydroxide ions, making the solution basic. Conversely, if a salt comes from a strong acid and a weak base, the cation from the weak base may release protons to water, making the solution acidic.
In essence:
  • Ions from strong acids or bases tend not to react with water, leaving the pH unchanged and the solution neutral.
  • Anions from weak acids can make a solution basic through hydrolysis.
  • Cations from weak bases might cause a solution to be acidic.
Acidic Solutions
An acidic solution is characterized by an increase in the concentration of hydrogen ions (H鈦�) in water. This often occurs when a salt created from a weak base and a strong acid is dissolved. The cation from the weak base hydrolyzes, releasing hydrogen ions, thus increasing the solution's acidity.
Take sodium bisulfate (\( ext{NaHSO}_{4}\)): the \( ext{HSO}_{4}^{-}\) ion can donate a proton to form sulphuric acid's first dissociation product, \( ext{H}_2 ext{SO}_4\), making the solution acidic. In such cases, you鈥檒l find:
  • The presence of ions from weak bases are more likely to release protons into the water.
  • The solution's pH will be less than 7.
Basic Solutions
A basic solution happens when there is an increase in hydroxide ions (\( ext{OH}^-\)) in the water. This typically results if a salt comes from a strong base and a weak acid. The anion from the weak acid tends to interact with water molecules to produce hydroxide ions, making the solution basic.
An example would be potassium cyanide (\( ext{KCN}\)): The \( ext{CN}^{-}\) ion from the weak acid hydrogen cyanide (\( ext{HCN}\)) hydrolyzes to form \( ext{OH}^{-}\), thus creating a basic environment. Characteristics include:
  • The resulting pH is greater than 7.
  • Anion hydrolysis of weak acids contributes to the concentration of hydroxide ions.
Neutral Solutions
Neutral solutions have a pH close to 7, signifying no net change in hydrogen or hydroxide ion concentration. When salts formed from strong acids and strong bases dissolve in water, they typically create neutral solutions. This is because the ions from both strong acids and bases are generally non-reactive with water and do not alter the pH.
For instance, calcium chloride (\( ext{CaCl}_{2}\)) in water dissociates into \( ext{Ca}^{2+}\) and \( ext{Cl}^{-}\) ions. Both ions arise respectively from calcium hydroxide (\( ext{Ca(OH)}_{2}\)) and hydrochloric acid (\( ext{HCl}\)), both strong, hence the solution remains neutral in water. Typically:
  • Ions from strong acids or bases don鈥檛 react with water.
  • Such solutions don鈥檛 change the concentration of \( ext{H}^{+}\) or \( ext{OH}^{-}\).

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

The value of \(K_{\mathrm{a}}\) in water at \(25^{\circ} \mathrm{C}\) for trichloroacetic acid, \(\mathrm{Cl}_{3} \mathrm{CCOOH}(a q)\), is \(2.2 \times 10^{-1} \mathrm{M} .\) Calculate the \(\mathrm{pH}\) and the concentrations of the other species in a \(0.030-\mathrm{M}\) aqueous solution of \(\mathrm{Cl}_{3} \mathrm{CCOOH}(a q)\).

Use Le Ch芒telier's principle to predict the direction in which the equilibrium described by the following equation shifts in response to the indicated change in conditions: $$ \begin{aligned} \mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COOH}(a q) &+\mathrm{H}_{2} \mathrm{O}(l) \leftrightharpoons \\ \mathrm{H}_{3} \mathrm{O}^{+}(a q)+\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COO}^{-}(a q) \Delta H_{\mathrm{rxn}}^{\circ}=0 \end{aligned} $$ (a) evaporation of water from the solution at a fixed temperature (b) decrease in the temperature of the solution (c) addition of \(\mathrm{KC}_{6} \mathrm{H}_{5} \mathrm{COO}(s)\) (d) addition of \(\mathrm{NH}_{3}(g)\)

What is the \(\mathrm{pH}\) of a \(2.60 \times 10^{-8} \mathrm{M}\) solution of \(\mathrm{HCl}(a q)\) at \(25^{\circ} \mathrm{C} ?\) (Hint: What must you also consider at this acid concentration?)

A saturated solution of \(\mathrm{Sr}(\mathrm{OH})_{2}(a q)\) at \(25^{\circ} \mathrm{C}\) has a measured \(\mathrm{pH}\) of \(13.50 .\) Estimate the solubility of \(\mathrm{Sr}(\mathrm{OH})_{2}(s)\) in water at \(25^{\circ} \mathrm{C}\) in grams per 100 milliliters of solution.

Calculate \(\left[\mathrm{H}_{5} \mathrm{O}^{+}\right],\left[\mathrm{ClO}_{4}^{-}\right]\), and \(\left[\mathrm{OH}^{-}\right]\) in an aqueous solution that is \(0.150 \mathrm{M}\) in \(\mathrm{HClO}_{4}(a q)\) at \(25^{\circ} \mathrm{C}\). Is the solution acidic or basic?
See all solutions

Recommended explanations on Chemistry Textbooks

Chemical Analysis

Read Explanation

The Earths Atmosphere

Read Explanation

Inorganic Chemistry

Read Explanation

Ionic and Molecular Compounds

Read Explanation

Making Measurements

Read Explanation

Nuclear Chemistry

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.