X-Y Calculation In Chemistry

By Samuel Orugbo

X-Y Calculation in Chemistry is borne out of the necessity to introduce young intellects into been solution provider rather problem creators.

By using the Problem solving mode (PSM) technique employed in this book, young lads are brain prepared to learn different topics in chemistry by simply going through the solved problems and attempting the subsequent evaluations that follows.

With the mode employed in this book, science oriented kids are able to note the discrepancy that exist between theoretically predicted values and practical obtained data from the lab.

• Language: English
• Publisher: Samuel Orugbo
• Release date: Aug 31, 2017
• ISBN: 9781370935598

Book preview

X-Y Calculation In Chemistry

By

Orugbo Samuel

All rights reserved.

No part(s) of this publication may be reproduced, stored in or introduced into a retrieval system or transmitted in any form or by any means ( electronically, mechanical, photocopying, recording or otherwise) without the prior written permission of both the copy right owner and sole distributor of this book.

Copyright (c) 2017

Orugbo Samuel

ISBN: 9781370935598

Smashwords Edition

Published by:

Alphikka Technologies

#1 Olodu Close, Off Olu-Obasanjo Road

Port Harcourt, Nigeria.

Tel: [phone]

Email: [e-mail]

Dedication

This piece of work is fully dedicated to my Heavenly Jehovah himself and to all my well-wishers, who one way or the other contributed to this book.

Preface

X-Y Calculation in Chemistry is borne out of the necessity to introduce young intellects into been solution provider rather problem creators.

By using the Problem solving mode (PSM) technique employed in this book, young lads are brain prepared to learn different topics in chemistry by simply going through the solved problems and attempting the subsequent evaluations that follows.

With the mode employed in this book, science oriented kids are able to note the discrepancy that exist between theoretically predicted values and practical obtained data from the lab.

Acknowledgements

My profound gratitude goes to God almighty for his Guardian and wisdom

My sincere gratitude also goes to A.B Ababio a renowned chemist who contributed immensely to this work.

My gratitude also goes to the author of Outline chemistry.

Table of Contents

DEDICATION

PREFACE

ACKNOWLEDGMENTS

CHAPTER ONE

Mole as a Measuring Unit in Chemistry

CHAPTER TWO

Application Of The Mole Concept

Mass – Mass Calculation

Mass – Volume Calculation

Volume-Volume Calculation

Percentage Composition Evaluation

Water Of Crystallization

CHAPTER THREE

Volumetric Analysis Calculation

MOLARITY

Percentage Purity Calculation

PH Caculation

CHAPTER FOUR

Gravimetric Analysis Caculation

Emperical and Molecular Formula Evaluation

Isotopic Calculation

Miscellaneous Problems

Molar Mass Calculation

CHAPTER FIVE

Electrolysis

Calculation On Faraday’s First Law Of Electrolysis

Calculation Involving Second Law of Electrolysis

Balancing Redox Equations

Oxidation Number

CHAPTER SIX

Boyle’s Law Calculation

Charles Law Calculation

General Gas Equation

Ideal Gas Law Calculation

Graham Law of Diffusion Calculation

Partial Pressures Calculation

Gay -Lussacs Law Calculation

Avogadro’s Hypothesis Calculation

Miscellaneous Solutions

CHAPTER SEVEN

Solubility

Graphical Calculation On Solubility

Solubility Product (ksp)

CHAPTER EIGHT

Energy Calculation

Enthalpy Calculation

Entropy and The Free Energy Calculation

Relationship Between ΔS AND ΔG

Equilibrium Constant, Free Energy and Electrode Potential

Mass Defect Calculation

Half-Life Calculation

CHAPTER ONE

1.1 Mole as a Measuring Unit in Chemistry

Every discipline has it synthesis. So also chemistry has it mode of operation.

The mole is the basic unit of measurement in chemistry. Substances are determined volumetrically or gravimetrically using the mole concept. It is mathematically related with the molar mass as;

Mole = Mass/Molar Mass

Or, Amount in Mole = Reacting Mass/Molar Mass…you can add that to your formula bag.

EXAMPLE 1.1

How many moles are there in 0.5g of oxygen gas? Given that the molar mass of oxygen is 32g/mol.

SOLUTION

Amount in Mole = Reacting Mass/Molar Mass

R.M = Reacting Mass = 0.5g

M.M = Molar Mass = 32g/mol

Mole = 0.5g/32gmol-1 = 0.5g/32g = 0.0156 moles

EXAMPLE 1.2

What mass of hydrogen chloride is present in 0.841 moles of the gas? {HCl = 36.5}

SOLUTION

Amount in mole = 0.84

M.M of HCl = 36.5

R.M of HCl =?

Amount in Mole of HCl = R. M of HCl/M.M of HCl

R.M of HCl = 0.84mol * 36.5gmol-1 = 30.66g ans.

EVALUATION

How many moles of calcium trioxocarbonate (IV) (CaCO3) is present in 8.4g of the compound? CaCO3 = 100

Ans = 0.084 mole.

Hope you got it? If not try again

For the purpose of this book, R.M and M.M shall stand for reacting mass and molar masses respectively. Be warned; don’t use them in any other standard examinations, without defining them.

CHAPTER TWO

Application of the Mole Concept

2.1 Mass – Mass Calculation

In most chemistry problems we are often given the mass of one substance and we are asked to find the mass of another. This mode of calculation is known as mass – mass calculation.

We are expected to have a sound knowledge of how to balance chemical equations in other to be effective in this course.

EXAMPLE 2.1

What mass of carbon (IV) oxide (CO2) would be formed, when 8.7g of HCl react with CaCO3? [C = 12, Ca = 40, O = 16, H = 1, Cl = 35.5]

SOLUTION

First we write the chemical equation to show the reaction and it must be balanced.

2HCl (l) + CaCO3 (s) => CaCl2(s) + CO2(g) + H20 (l)

Since we are given the mass of HCl and asked to calculate that of

CO2, we shall only then consider the two molecules i.e. HCl and

CO2 involved. Their mole