Textbook Question
A metal (M) forms a compound with the formula MCl3. If the compound contains 65.57% Cl by mass, what is the identity of the metal?
2392
views
2
comments
Ch.3 - Molecules and Compounds
Tro6th EditionChemistry: A Molecular ApproachISBN: 9780137832217
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch.1 - Matter, Measurement & Problem Solving90
- Ch.2 - Atoms & Elements94
- Ch.3 - Molecules and Compounds103
- Ch.4 - Chemical Reactions and Chemical Quantities46
- Ch.5 - Introduction to Solutions and Aqueous Solutions65
- Ch.6 - Gases100
- Ch.7 - Thermochemistry85
- Ch.8 - The Quantum-Mechanical Model of the Atom51
- Ch.9 - Periodic Properties of the Elements79
- Ch.10 - Chemical Bonding I: The Lewis Model70
- Ch.11 - Chemical Bonding II: Molecular Shapes, VSEPR & MO Theory68
- Ch.12 - Liquids, Solids & Intermolecular Forces44
- Ch.13 - Solids & Modern Materials42
- Ch.14 - Solutions77
- Ch.15 - Chemical Kinetics88
- Ch.16 - Chemical Equilibrium57
- Ch.17 - Acids and Bases121
- Ch.18 - Aqueous Ionic Equilibrium126
- Ch.19 - Free Energy & Thermodynamics80
- Ch.20 - Electrochemistry87
- Ch.21 - Radioactivity & Nuclear Chemistry61
- Ch.22 - Organic Chemistry114
Chapter 3, Problem 127
Estradiol is a female sexual hormone that is responsible for the maturation and maintenance of the female reproductive system. Elemental analysis of estradiol gives the following mass percent composition: C 79.37%, H 8.88%, O 11.75%. The molar mass of estradiol is 272.37 g/mol. Find the molecular formula of estradiol.
Verified step by step guidance1
insert step 1: Assume you have 100 g of estradiol, which allows you to directly convert the mass percentages to grams: C = 79.37 g, H = 8.88 g, O = 11.75 g.
insert step 2: Convert the masses of each element to moles by dividing by their respective atomic masses: C (12.01 g/mol), H (1.008 g/mol), O (16.00 g/mol).
insert step 3: Determine the mole ratio of the elements by dividing each element's mole value by the smallest number of moles calculated in step 2.
insert step 4: If necessary, multiply the mole ratios by a whole number to get whole numbers for each element in the empirical formula.
insert step 5: Calculate the empirical formula mass and divide the molar mass of estradiol (272.37 g/mol) by the empirical formula mass to find the ratio needed to convert the empirical formula to the molecular formula.
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Empirical Formula
The empirical formula represents the simplest whole-number ratio of the elements in a compound. To determine the empirical formula, the mass percent composition of each element is converted to moles, and then the ratio of these moles is simplified to the smallest whole numbers. This provides a foundational understanding of the compound's composition before determining the molecular formula.
Recommended video:
Guided course
02:26
Empirical vs Molecular Formula
Molecular Formula
The molecular formula indicates the actual number of atoms of each element in a molecule of a compound. It can be derived from the empirical formula by multiplying the subscripts by a whole number, which is determined by dividing the compound's molar mass by the molar mass of the empirical formula. This concept is crucial for identifying the specific structure and composition of estradiol.
Molar Mass Calculation
Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is calculated by summing the atomic masses of all atoms in the molecular formula. Understanding how to calculate molar mass is essential for converting between grams and moles, which is necessary for determining both empirical and molecular formulas in chemical analysis.
Recommended video:
Guided course
03:12Molar Mass Calculation Example
Related Practice
Textbook Question
Combustion analysis of a 13.42-g sample of equilin (which contains only carbon, hydrogen, and oxygen) produces 39.61 g CO2 and 9.01 g H2O. The molar mass of equilin is 268.34 g/mol. Find its molecular formula.
3137
views
Textbook Question
Fructose is a common sugar found in fruit. Elemental analysis of fructose gives the following mass percent composition: C 40.00%, H 6.72%, O 53.28%. The molar mass of fructose is 180.16 g/mol. Find the molecular formula of fructose.
2020
views
Textbook Question
Determine the chemical formula of each compound and then use it to calculate the mass percent composition of each constituent element. d. cobalt(II) bromide
753
views
Textbook Question
Estrone, which contains only carbon, hydrogen, and oxygen, is a female sexual hormone in the urine of pregnant women. Combustion analysis of a 1.893-g sample of estrone produces 5.545 g of CO2 and 1.388 g H2O. The molar mass of estrone is 270.36 g/mol. Find its molecular formula.
1481
views
1
rank
Textbook Question
A metal (M) forms an oxide with the formula M2O. If the oxide contains 16.99% O by mass, what is the identity of the metal?
1477
views