EBK INTRODUCTION TO CHEMISTRY
5th Edition
ISBN: 9781260162165
Author: BAUER
Publisher: MCGRAW HILL BOOK COMPANY
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Textbook Question
Chapter 4, Problem 61QP
You have two colorless gases, each made of sulfur and oxygen. If they have different percent compositions, can they be the same substance?
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Mole is the term used to express the quantities of substances involved in a chemical reaction. Mole is defined as the amount of a substance that contains Avogadro's number of particles
(atoms, ions, molecules, etc.). Avogadro's number is defined as the number of atoms present in 12 g of carbon-12 isotope, with a numerical value equal to 6.022 x 1023. The mole is a
unit similar to a dozen; one dozen
equivalent to 12 the same way that one mole is equivalent to 6.022 x 1023.
You could use this information to write equalities:
12 molecules of H2O = 1 dozen of H2O
6.022 x 1023 molecules of H2O = 1 mol of H2O
For example, if I had 18 molecules of water, I would have
18 molecules of water x
dozen of water
= 1.5 dozen of water
12 molecules of water
Molar mass is the mass in grams of 1 mol of substance numerically equal to molecular weight in amu (atomic mass unit). Mass is a measure of quantity, and when you use a balance to
weigh a sample, the scale is using a set of standards to determine…
Imagine that all our balances displayed mass in units of slugs instead of grams.
Would we still want to use the number , 6.022×10236.022×1023, for Avogadro's number? Why or why not?
Yes, because the number of particles in one mole does not depend on the mass of the particles.
No, because we would use the number of atoms in exactly 12 slugs of carbon-12 to define the mole.
Yes, because the value of Avogadro's number is a universal constant.
No, because we would not be able to use carbon-12 to define the mole.
What number would we want to use instead? (A slug is equal to 14954 g.)
Express your answer using four significant figures.
Percent Composition from a Chemical Formula
The percent composition of a compound can also be determined from the formula of the
compound. The subscripts in the formula are first used to calculate the mass of each element in
one mole of the compound. That is divided by the molar mass of the compound and multiplied
by 100%100%.
mass of element in 1 mol
% by mass =
x 100%
molar mass of compound
Step by Step
Calculation of Percent
Composition of a compound
Example:
A certain newly synthesized compound is known to contain the elements zinc and oxygen. When
a 20.00g20.00g sample of the compound is decomposed, 16.07gof zinc remains. Determine the
percent composition of the compound.
Step 1: List the known quantities and plan the problem.
Known
Mass of compound =20.00g
Mass of Zn=16.07gZn
Unknown
Percent Zn=?%
Percent O=?%
Step 2: Subtract to find the mass of oxygen in the compound. Divide each element's mass by the
mass of the compound to find the percent by mass.
Mass of oxygen = 20.00 g –…
Chapter 4 Solutions
EBK INTRODUCTION TO CHEMISTRY
Ch. 4 - Prob. 1QCCh. 4 - Prob. 2QCCh. 4 - Prob. 3QCCh. 4 - Prob. 4QCCh. 4 - Prob. 1PPCh. 4 - Prob. 2PPCh. 4 - Prob. 3PPCh. 4 - Prob. 4PPCh. 4 - Prob. 5PPCh. 4 - Prob. 6PP
Ch. 4 - Prob. 7PPCh. 4 - Prob. 8PPCh. 4 - Prob. 9PPCh. 4 - Prob. 10PPCh. 4 - Prob. 11PPCh. 4 - Prob. 12PPCh. 4 - Prob. 13PPCh. 4 - Prob. 14PPCh. 4 - Prob. 15PPCh. 4 - Prob. 16PPCh. 4 - Prob. 17PPCh. 4 - Prob. 18PPCh. 4 - Prob. 19PPCh. 4 - Prob. 20PPCh. 4 - Prob. 21PPCh. 4 - Prob. 22PPCh. 4 - Prob. 23PPCh. 4 - Prob. 1QPCh. 4 - Prob. 2QPCh. 4 - Prob. 3QPCh. 4 - Prob. 4QPCh. 4 - Prob. 5QPCh. 4 - Prob. 6QPCh. 4 - Lithium carbonate, Li2CO3 , contains 18.8 lithium...Ch. 4 - Prob. 8QPCh. 4 - Prob. 9QPCh. 4 - Prob. 10QPCh. 4 - Prob. 11QPCh. 4 - Prob. 12QPCh. 4 - Prob. 13QPCh. 4 - Prob. 14QPCh. 4 - Prob. 15QPCh. 4 - Prob. 16QPCh. 4 - Prob. 17QPCh. 4 - Prob. 18QPCh. 4 - Prob. 19QPCh. 4 - Prob. 20QPCh. 4 - Prob. 21QPCh. 4 - Prob. 22QPCh. 4 - Prob. 23QPCh. 4 - Prob. 24QPCh. 4 - Prob. 25QPCh. 4 - Prob. 26QPCh. 4 - Prob. 27QPCh. 4 - Calculate the molar mass of each of the following...Ch. 4 - Prob. 29QPCh. 4 - Prob. 30QPCh. 4 - Prob. 31QPCh. 4 - Prob. 32QPCh. 4 - Prob. 33QPCh. 4 - Prob. 34QPCh. 4 - Prob. 35QPCh. 4 - Prob. 36QPCh. 4 - Prob. 37QPCh. 4 - Prob. 38QPCh. 4 - Prob. 39QPCh. 4 - Prob. 40QPCh. 4 - Prob. 41QPCh. 4 - Prob. 42QPCh. 4 - Prob. 43QPCh. 4 - Calculate the mass of 0.750 mol of the following...Ch. 4 - Prob. 45QPCh. 4 - Prob. 46QPCh. 4 - A sample of ammonia, NH3 , weights 30.0 g....Ch. 4 - Prob. 48QPCh. 4 - Which of these substance has the most atoms per...Ch. 4 - Which of these substances has the atoms per mole?...Ch. 4 - A raindrop weighs 0.050 g. How many molecules of...Ch. 4 - A gain of sand weighs 7.7104g . How many formula...Ch. 4 - How many formula units are in 250.0 g of the...Ch. 4 - How many formula units are in 375.0 g of the...Ch. 4 - How many atoms (or ions) of each element are in...Ch. 4 - How many atoms (or ions) of each element are in...Ch. 4 - What is the mass of 6.41022 molecules of SO2?Ch. 4 - What is the mass of 1.81021 molecules of H2SO4?Ch. 4 - Which compound, NH3,NH4Cl,NO2,orN203, contains the...Ch. 4 - Which compound, NaCl,PC13,CaC12,orHCIO2, contains...Ch. 4 - You have two colorless gases, each made of sulfur...Ch. 4 - Describe some uses for the percent composition of...Ch. 4 - What is the difference between an empirical...Ch. 4 - Why do we normally use an empirical formula...Ch. 4 - Which of the following molecules have an empirical...Ch. 4 - Which of the following substances have an...Ch. 4 - Prob. 67QPCh. 4 - What is the empirical formula of each of the...Ch. 4 - Prob. 69QPCh. 4 - Prob. 70QPCh. 4 - Which of the following compounds of nitrogen and...Ch. 4 - Which of the following compounds of carbon and...Ch. 4 - What are the empirical formulas of the compounds...Ch. 4 - What are the empirical formulas of the compounds...Ch. 4 - Eugenol, a chemical substance with the flavor of...Ch. 4 - One of the compounds in cement has the following...Ch. 4 - The explosive trinitrotoluene (TNT) has the...Ch. 4 - Strychnine (rat poison) has the composition...Ch. 4 - An unknown organic compound was determined to have...Ch. 4 - Prob. 80QPCh. 4 - Prob. 81QPCh. 4 - Prob. 82QPCh. 4 - Prob. 83QPCh. 4 - Prob. 84QPCh. 4 - Prob. 85QPCh. 4 - Prob. 86QPCh. 4 - What is the percent composition of each of the...Ch. 4 - Prob. 88QPCh. 4 - Prob. 89QPCh. 4 - Prob. 90QPCh. 4 - Prob. 91QPCh. 4 - Prob. 92QPCh. 4 - Prob. 93QPCh. 4 - Prob. 94QPCh. 4 - Prob. 95QPCh. 4 - Prob. 96QPCh. 4 - Prob. 97QPCh. 4 - Prob. 98QPCh. 4 - Prob. 99QPCh. 4 - Prob. 100QPCh. 4 - Prob. 101QPCh. 4 - Prob. 102QPCh. 4 - Prob. 103QPCh. 4 - Prob. 104QPCh. 4 - Prob. 105QPCh. 4 - Prob. 106QPCh. 4 - Prob. 107QPCh. 4 - Prob. 108QPCh. 4 - Prob. 109QPCh. 4 - Prob. 110QPCh. 4 - Prob. 111QPCh. 4 - Prob. 112QPCh. 4 - Prob. 113QPCh. 4 - Prob. 114QPCh. 4 - Prob. 115QPCh. 4 - Prob. 116QPCh. 4 - Prob. 117QPCh. 4 - How many molecules are present in 15.43 g of butyl...Ch. 4 - Prob. 119QPCh. 4 - Prob. 120QPCh. 4 - Prob. 121QPCh. 4 - Prob. 122QPCh. 4 - Prob. 123QPCh. 4 - Prob. 124QPCh. 4 - Prob. 125QPCh. 4 - Prob. 126QPCh. 4 - Prob. 127QPCh. 4 - Prob. 128QPCh. 4 - Prob. 129QPCh. 4 - Prob. 130QPCh. 4 - Prob. 131QPCh. 4 - Prob. 132QPCh. 4 - Prob. 133QPCh. 4 - Prob. 134QPCh. 4 - Prob. 135QPCh. 4 - Prob. 136QPCh. 4 - Prob. 137QPCh. 4 - Prob. 138QPCh. 4 - Prob. 139QPCh. 4 - Prob. 140QPCh. 4 - Prob. 141QPCh. 4 - Prob. 142QPCh. 4 - Prob. 143QPCh. 4 - Prob. 144QPCh. 4 - Prob. 145QPCh. 4 - Prob. 146QPCh. 4 - Prob. 147QPCh. 4 - Prob. 148QPCh. 4 - Prob. 149QPCh. 4 - Prob. 150QPCh. 4 - Prob. 151QPCh. 4 - Prob. 152QP
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