Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 4: Problem 5

You are presented with a white solid and told that due to careless labeling it is not clear if the substance is barium chloride, lead chloride, or zinc chloride. When you transfer the solid to a beaker and add water, the solid dissolves to give a clear solution. Next an $\mathrm{Na}_{2} \mathrm{SO}_{4}(a q)$ solution is added and a white precipitate forms. What is the identity of the unknown white solid? [Section 4.2\(]\)

Short Answer

Expert verified
The unknown white solid is either barium chloride (BaCl₂) or lead chloride (PbCl₂), as both of these substances form insoluble sulfate salts when reacted with sodium sulfate, resulting in a white precipitate. Zinc chloride can be ruled out, as it forms a soluble sulfate salt with no precipitate. Further tests would be needed to confirm the exact identity of the solid.

Step by step solution

01

Write the general form of the reactions

First, we need to write the general form of the reactions of the unknown solid with water and with sodium sulfate. Since all three possible solids are in the form of metal chlorides (MCl₂), the general form of their reactions can be written as: Reaction with water: MCl₂(s) + H₂O(l) → M²⁺(aq) + 2 Cl⁻(aq) Reaction with sodium sulfate: M²⁺(aq) + 2 Cl⁻(aq) + 2 Na⁺(aq) + SO₄²⁻(aq) → M(??) + 2 NaCl(aq)
02

Identify the products formed in the reaction with sodium sulfate

Using the solubility rules, we can predict the products formed when each of the possible metal cations reacts with sulfate ions: - Barium sulfate (BaSO₄): Insoluble - Lead sulfate (PbSO₄): Insoluble - Zinc sulfate (ZnSO₄): Soluble Based on this information, we can rewrite the second equation for each metal cation: Reaction with sodium sulfate (barium case): Ba²⁺(aq) + 2 Cl⁻(aq) + 2 Na⁺(aq) + SO₄²⁻(aq) → BaSO₄(s) + 2 NaCl(aq) Reaction with sodium sulfate (lead case): Pb²⁺(aq) + 2 Cl⁻(aq) + 2 Na⁺(aq) + SO₄²⁻(aq) → PbSO₄(s) + 2 NaCl(aq) Reaction with sodium sulfate (zinc case): Zn²⁺(aq) + 2 Cl⁻(aq) + 2 Na⁺(aq) + SO₄²⁻(aq) → ZnSO₄(aq) + 2 NaCl(aq)
03

Compare the results with the given observations

The initial observation states that when the unknown solid is added to water, it dissolves to give a clear solution. This confirms that the metal chloride is soluble in water, which is true for all three candidates (barium chloride, lead chloride, and zinc chloride). The second observation states that when an aqueous solution of sodium sulfate is added, a white precipitate forms. We can now use this information to eliminate possibilities based on the products formed in the second equation: - Barium case: A white precipitate (BaSO₄) is formed. - Lead case: A white precipitate (PbSO₄) is formed. - Zinc case: No precipitate is formed (ZnSO₄ is soluble).
04

Identify the unknown solid

Since a white precipitate forms when the sodium sulfate solution is added, the unknown solid must be one of the reactants forming an insoluble sulfate salt. Based on our analysis in step 3, we can conclude that the unknown solid is either: - Barium chloride (BaCl₂) or - Lead chloride (PbCl₂) However, we can not definitively identify the unknown solid as either barium chloride or lead chloride solely based on the given observations. Further tests would be needed to confirm the exact identity of the solid.

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

Copper exists in the form of \(\mathrm{CuFeS}_{2}\) in copper ore. Copper is isolated in a two-step process. First, CuFeS \(_{2}\) is heated with \(\mathrm{SiO}_{2}\) in the presence of oxygen to form copper(I) sulfide, $\mathrm{CuS:} 2 \mathrm{CuFeS}_{2}+2 \mathrm{SiO}_{2}(s)+4 \mathrm{O}_{2}(g) \longrightarrow \mathrm{Cu}_{2} \mathrm{~S}(s)+$ \(2 \mathrm{FeSiO}_{3}(s)+3 \mathrm{SO}_{2}(g) . \mathrm{Cu}_{2} \mathrm{~S}\) is then heated with oxygen to form copper and \(\mathrm{SO}_{2}(g)\). (a) Write the balanced chemical equation for the second reaction. (b) Which atoms from which compounds are being oxidized, and which atoms from which compounds are being reduced? (c) How many grams of copper would be isolated from \(85.36 \mathrm{~g}\) of \(\mathrm{CuFeS}_{2}\) in copper ore?

Using solubility guidelines, predict whether each of the following compounds is soluble or insoluble in water: (a) \(\mathrm{Hg}_{2} \mathrm{SO}_{4}\) (b) \(\mathrm{NH}_{4} \mathrm{OH}\), (c) \(\mathrm{Ni}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}\) (d) \(\mathrm{AgNO}_{3}\), (e) FeCO \(_{3}\)

A solution is made by mixing \(1.5 \mathrm{~g}\) of \(\mathrm{LiOH}\) and $23.5 \mathrm{~mL}\( of \)1.000 \mathrm{M}$ HNO3. (a) Write a balanced equation for the reaction that occurs between the solutes. (b) Calculate the concentration of each ion remaining in solution. (c) Is the resulting solution acidic or basic?

A sample of \(8.69 \mathrm{~g}\) of \(\mathrm{Zn}(\mathrm{OH})_{2}\) is added to \(155.0 \mathrm{~mL}\) of \(0.750 \mathrm{M} \mathrm{H}_{2} \mathrm{SO}_{4} .\) (a) Write the chemical equation for the reaction that occurs. (b) Which is the limiting reactant in the reaction? (c) How many moles of \(\mathrm{Zn}(\mathrm{OH})_{2}, \mathrm{H}_{2} \mathrm{SO}_{4},\) and \(\mathrm{ZnSO}_{4}\) are present after the reaction is complete?

Citric acid, \(\mathrm{C}_{6} \mathrm{H}_{8} \mathrm{O}_{7}\), is a triprotic acid. It occurs naturally in citrus fruits like lemons and has applications in food flavouring and preservatives. A solution containing an unknown concentration of the acid is titrated with KOH. It requires $23.20 \mathrm{~mL}\( of \)0.500 \mathrm{M} \mathrm{KOH}$ solution to titrate all three acidic protons in \(100.00 \mathrm{~mL}\) of the citric acid solution. Write a balanced net ionic equation for the neutralization reaction, and calculate the molarity of the citric acid solution.
See all solutions

Recommended explanations on Chemistry Textbooks

Chemical Reactions

Read Explanation

Chemical Analysis

Read Explanation

Physical Chemistry

Read Explanation

Inorganic 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