   # One of the chemical controversies of the nineteenth century concerned the element beryllium (Be). Berzelius originally claimed that beryllium was a trivalent element (forming Be 3+ ions) and that it gave an oxide with the formula Be 2 O 3 . This resulted in a calculated atomic mass of 13.5 for beryllium. In formulating his periodic table, Mendeleev proposed that beryllium was divalent (forming Be 2+ ions) and that it gave an oxide with the formula Be 2 O 3 . This assumption gives an atomic mass of 9.0. In 1894, A. Combes ( Comptes Rendus 1894, p. 1221) reacted beryllium with the anion C 5 H 7 O 2 − and measured the density of the gaseous product. Combes’s data for two different experiments are as follows: I II Mass 0.2022 g 0.2224 g Volume 22.6 cm 3 26.0 cm 3 Temperature 13°C 17°C Pressure 765.2 mm Hg 764.6 mm If beryllium is a divalent metal, the molecular formula of the product will be Be(C 5 H 7 O 2 ) 2 ; if it is trivalent, the formula will be Be(C 5 H 7 O 2 ) 3 . Show how Combes’s data help to confirm that beryllium is a divalent metal. ### Chemistry: An Atoms First Approach

2nd Edition
Steven S. Zumdahl + 1 other
Publisher: Cengage Learning
ISBN: 9781305079243

#### Solutions

Chapter
Section ### Chemistry: An Atoms First Approach

2nd Edition
Steven S. Zumdahl + 1 other
Publisher: Cengage Learning
ISBN: 9781305079243
Chapter 8, Problem 138AE
Textbook Problem
159 views

## One of the chemical controversies of the nineteenth century concerned the element beryllium (Be). Berzelius originally claimed that beryllium was a trivalent element (forming Be3+ ions) and that it gave an oxide with the formula Be2O3. This resulted in a calculated atomic mass of 13.5 for beryllium. In formulating his periodic table, Mendeleev proposed that beryllium was divalent (forming Be2+ ions) and that it gave an oxide with the formula Be2O3. This assumption gives an atomic mass of 9.0. In 1894, A. Combes (Comptes Rendus 1894, p. 1221) reacted beryllium with the anion C5H7O2−and measured the density of the gaseous product. Combes’s data for two different experiments are as follows:   I II Mass 0.2022 g 0.2224 g Volume 22.6 cm3 26.0 cm3 Temperature 13°C 17°C Pressure 765.2 mm Hg 764.6 mm If beryllium is a divalent metal, the molecular formula of the product will be Be(C5H7O2)2; if it is trivalent, the formula will be Be(C5H7O2)3. Show how Combes’s data help to confirm that beryllium is a divalent metal.

Interpretation Introduction

Interpretation: From the given data, it should be confirmed that beryllium is a divalent element.

Concept introduction:

• Ideal gas equation in terms of Density,

Density=Pressure×Molecular massR×Temperature

### Explanation of Solution

Explanation

• To find: The molar mass of data set 1

Molarmass=209g/mol

Ideal gas equation in terms of Density,

Density=Pressure×Molecular massR×TemperatureMolecular mass=Density×R×TemperaturePressureSince,Density=MassVolumeMolecular mass=Mass×R×Temperature(T)Pressure(P)×Volume(V)

Here,Mass=0.2022gR=0.08206LatmKmolT=13°C=286KK=°C+273=13°C+273=286KP=765.2mmHg=765.2torr=1.006atm1atm=760torr

765.0×1atm760=1.006atmV=22.6cm3=22.6×10-3Lsince,1L=1000cm3Molecular mass=0.20220.08206LatmKmol×286K1.006atm×22.6×10-3L=209g/mol

• To find: The molar mass of data set 2

Molarmass=202g/mol

Density=Pressure×Molecular massR×TemperatureMolecular mass=Density×R×TemperaturePressureSince,Density=MassVolumeMolecular mass=Mass×R×Temperature(T)Pressure(P)×Volume(V)Here,Mass=0

### Still sussing out bartleby?

Check out a sample textbook solution.

See a sample solution

#### The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started

Find more solutions based on key concepts
In this nation, stringent controls make it difficult to obtain a bogus nutrition credential. T F

Nutrition: Concepts and Controversies - Standalone book (MindTap Course List)

Problem 8-6 The [OH-] of an aqueous solution is M. What is its [H3O+]?

Introduction to General, Organic and Biochemistry

Does the cell cycle refer to mitosis as well as meiosis?

Human Heredity: Principles and Issues (MindTap Course List)

Why is degenerate matter so difficult to compress?

Horizons: Exploring the Universe (MindTap Course List)

A woman wishing to know the height of a mountain measures the angle of elevation of the mountaintop as 12.0. Af...

Physics for Scientists and Engineers, Technology Update (No access codes included)

What is refraction?

Oceanography: An Invitation To Marine Science, Loose-leaf Versin 