Ch.3 - Chemical ReactionsSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Combustion analysis is a technique where an organic compound is combusted (exploded!!!) and the products are quantitatively measured. 

Understanding Combustion Analysis

Concept #1: Combustion Analysis Determination 

In a combustion reaction an organic compound made of carbon and hydrogen or carbon, hydrogen and oxygen is combusted to form carbon dioxide and water as products. 

Example #1: A 0.2500 g sample contains carbon, hydrogen and oxygen and undergoes complete combustion to produce 0.3664 g of CO2 and 0.1500 g of H2O. What is the empirical formula of the compound?

Additional Problems
Thiophene contains only the elements carbon, hydrogen and sulfur. A sample weighing 7.96 g was burned in oxygen to give 16.65 g CO2 and 3.40 g of H2O. What is the empirical formula of thiophene? a) C2H2S b) C4H4S c) C2H4S3 d) C2H4S e) C4H4S3
If 3.25 g of butane (C4H10, M = 58.14) is burned (combusted) in the presence of excess O2, what is the mass of CO2 that forms, in g? Enter your answer with 2 decimal places and no units.
Vanillin, the dominant flavoring in vanilla, contains C, H, and O. When 1.05 g of this substance is completely combusted, 2.43 g of CO2 and 0.50 g of H2O are produced.What is the empirical formula of vanillin?
An organic compound was found to contain only C, H, and Cl. When a 1.60 -g sample of the compound was completely combusted in air, 3.75 g of CO2 was formed. In a separate experiment the chlorine in a 1.30 -g sample of the compound was converted to 1.65 g of AgCl.Determine the empirical formula of the compound.
When hydrocarbons are burned in a limited amount of air, both CO and CO2 form. When 0.460 g of a particular hydrocarbon was burned in air, 0.477 g of CO, 0.749 g of CO2, and 0.460 g of H2O were formed.What is the empirical formula of the compound?
When hydrocarbons are burned in a limited amount of air, both CO and CO2 form. When 0.460 g of a particular hydrocarbon was burned in air, 0.477 g of CO, 0.749 g of CO2, and 0.460 g of H2O were formed.How many grams of O2 were used in the reaction?
When hydrocarbons are burned in a limited amount of air, both CO and CO2 form. When 0.460 g of a particular hydrocarbon was burned in air, 0.477 g of CO, 0.749 g of CO2, and 0.460 g of H2O were formed.How many grams would have been required for complete combustion?
Estrone, which contains only carbon, hydrogen, and oxygen, is a female sexual hormone that occurs in the urine of pregnant women. Combustion analysis of a 1.893-g sample of estrone produced 5.543 g of CO2 and 1.388 g H2 O. The molar mass of estrone is 270.36 g/mol .Find the molecular formula for estrone.
Combustion analysis of a hydrocarbon produced 33.01 g CO2 and 13.52 g H2O.Calculate the empirical formula of the hydrocarbon.
Combustion analysis of naphthalene, a hydrocarbon used in mothballs, produced 8.80 g CO2 and 1.44 g H2 O.Calculate the empirical formula for naphthalene.
The foul odor of rancid butter is due largely to butyric acid, a compound containing carbon, hydrogen, and oxygen. Combustion analysis of a 4.30-g sample of butyric acid produced 8.59 g CO2 and 3.52 g H2 O.Find the empirical formula for butyric acid.
Tartaric acid is the white, powdery substance that coats sour candies such as Sour Patch Kids. Combustion analysis of a 12.01-g sample of tartaric acid-which contains only carbon, hydrogen, and oxygen-produced 14.08 g CO2 and 4.32 g H2 O.Find the empirical formula for tartaric acid.
A 2.52-g sample of a compound containing only carbon, hydrogen, nitrogen, oxygen, and sulfur was burned in excess oxygen to yield 4.23 g of CO2 and 1.01 g of H2O. Another sample of the same compound, of mass 4.14 g, yielded 2.11 g of SO3. A third sample, of mass 5.66 g, was burned under different conditions to yield 2.27 g of HNO3 as the only nitrogen containing product.Calculate the empirical formula of the compound.
A sample of a hydrocarbon is combusted completely in O2(g) to produce 24.01 g CO2(g), 4.917 g H2O(g), and 342 kJ of heat.What is the empirical formula of the hydrocarbon?
You may want to reference (Pages 98 - 102)Section 3.5 while completing this problem.The compound dioxane, which is used as a solvent in various industrial processes, is composed of C, H, and O atoms. Combustion of a 2.203-g sample of this compound produces 4.401 g CO2 and 1.802 g H2O. A separate experiment shows that it has a molar mass of 88.1 g/mol. Which of the following is the correct molecular formula for dioxane
Valproic acid, used to treat seizures and bipolar disorder, is composed of C, H, and O. A 0.165-g sample is combusted to produce 0.166 g of water and 0.403 g of carbon dioxide.What is the empirical formula for valproic acid?
Propenoic acid, C3H4O2, is a reactive organic liquid that is used in the manufacturing of plastics, coatings, and adhesives. An unlabeled container is thought to contain this liquid. A 0.376-g sample is combusted to produce 0.202 g of water and 0.427 g of carbon dioxide. You may want to reference (Pages 99 - 102)Section 3.5 while completing this problem.Is the unknown liquid propenoic acid?
Valproic acid, used to treat seizures and bipolar disorder, is composed of C, H, and O. A 0.165-g sample is combusted to produce 0.166 g of water and 0.403 g of carbon dioxide.If the molar mass is 144 g/mol, what is the molecular formula?
You may want to reference (Pages 99 - 102) Section 3.5 while completing this problem.The characteristic odor of pineapple is due to ethyl butyrate, a compound containing carbon, hydrogen, and oxygen. Combustion of 3.06 mg of ethyl butyrate produces 6.95 mg of CO2 and 2.84 mg of H2 O. What is the empirical formula of the compound?
You may want to reference (Pages 99 - 102) Section 3.5 while completing this problem.Nicotine, a component of tobacco, is composed of C, H, and N. A 5.775-mg sample of nicotine was combusted, producing 15.666 mg of CO2 and 4.491 mg of H2 O. What is the empirical formula for nicotine?
Combustion analysis of toluene, a common organic solvent, gives 6.45 mg of CO2 and 1.51 mg of H2 O. If the compound contains only carbon and hydrogen, what is its empirical formula?
Menthol, the substance we can smell in mentholated cough drops, is composed of C, H, and O. A 0.1106 -mg sample of menthol is combusted, producing 0.3112 mg of CO2 and 0.1275 mg of H2 O. What is the empirical formula for menthol?
Para-cresol is used as a disinfectant. A 0.3654 g sample of this compound that contains only C, H, and O, gave 1.0420 g CO2 and 0.2437 g H2O in a combustion analysis. Its molecular mass is 108.1g/mol. What is its molecular formula? a. C7H8Ob. C6H7Oc. C7H7O2d. C6H7O2e. C7H8O2
Combustion analysis of a 12.01 g sample of tartaric acid, which contains only  carbon, hydrogen, and oxygen, produced 14.08 g CO2 and 4.32 g H2O. a) What is the empirical formula of tartaric acid?             b) If 0.250 moles of the compound weighs 37.52 g, what is the molecular formula of the compound?  
The combustion of 4.16 grams of a compound which contains only C,H,O and F yields 7.7 g CO2 and 2.52 g H2O. Another sample of the compound with a mass of 3.63 g is found to contain 0.58 g F. What is the empirical formula of the compound? A. C3H8O2FB. C4H10OFC. C4H8OFD. C5H8O2F
A 4.05 g sample of a compound containing only C, H, and O was burned completely. The only combustion products were 10.942 g CO2 and 4.476 g H2O. What is the empirical formula of the compound?A) C7H7OB) C7H14O7C) CH2OD) C7H14OE) C6H12O
Combustion analysis of an unknown compound containing only carbon and hydrogen produced 4.554 g of CO2 and 2.322 g of H2O. What is the empirical formula of the compound?A) C4H10B) CH2 C) C2H5D) C5H2
Combustion analysis of 2.400 g of an unknown compound containing carbon, hydrogen, and oxygen produced 4.171 g of CO2 and 2.268 g of H2O. What is the empirical formula of the compound?A) C2H5O2B) C2H5OC) C2H10O3 D) C3H8O2
Isoeugenol is the compound which gives the characteristic odor to nutmeg and contains carbon, hydrogen, and oxygen. If a 0.500 g sample of isoeugenol is combusted it gives 1.341 g of CO2 and 0.329 g of H2O. Isoeugenol has a molecular weight of 164 g/mol. What is the molecular formula of isoeugenol?A) C8H4O4B) C10H12O2 C) C2HOD) C5H6O
A strip of pure copper metal weighing 3.178 g is heated in the presence of oxygen gas. In the process, all of the copper reacts with oxygen to form 3.978 g of a black copper oxide. What is the empirical formula for this copper oxide?Given that the molar mass of the compound is about 80 g, name this compound.
2.404 g of a compound were burned in oxygen and found to produce only 3.520 g CO2 (g), 2.564 g SO2 (g) and 1.440 g H2O (l). Determine the empirical formula of the compound.A) C2SH4B) C2SH2C) CSHD) C4SH2 E) C2S2H4
There are two binary compounds of mercury and oxygen. Heating either of them results in the decomposition of the compound, with oxygen gas escaping into the atmosphere while leaving a residue of pure mercury. Heating 0.6498 g of one of the compounds leaves a residue of 0.6018 g. Heating 0.4172 g of the other compound results in a mass loss of 0.016 g. Determine the empirical formula of each compound.
A compound contains only carbon, hydrogen, and oxygen. Combustion of 10.68 mg of the compound yields 16.01 mg CO2 and 4.37 mg H2O. The molar mass of the compound is 176.1 g/mol. What are the empirical and molecular formulas of the compound?
Combustion analysis of 63.8 mg of a C, H and O containing compound produced 145.0 mg of CO2 and 59.38 mg of H2O. What is the empirical formula for the compound?A) C5H2OB) CHOC) C3H6OD) C3H7OE) C6HO3
On combustion analysis, a 0.450 g sample of a chemical compound gives 0.418 g of water and 1.023 g of carbon dioxide. Assuming that the empirical formula of the compound is CxHyOz, find the values of x, y and z.
Combustion analysis of naphthalene, a hydrocarbon used in mothballs, produced 8.80 g CO2 and 1.44 g H2O. Calculate the empirical formula for naphthalene. 
Tartaric acid is the white, powdery substance that coats tart candies such as Sour Patch Kids. Combustion analysis of a 12.01 g sample of tartaric acid-which contains only carbon, hydrogen, and oxygen-produced 14.08 g CO2 and 4.32 g H2O. Determine the empirical formula for tartaric acid. 
A hydrocarbon  with general formula CxHy was burned completely in air, yielding 0.18 g of water and 0.44 g of carbon dioxide. Which formula could give such data?A. C2H2B. C2H4C. C2H6D. C6H6
Determine the empirical formula for a hydrocarbon if the complete combustion of a sample produces 5.28 g of CO2 and 1.62 g of H2O. 
Para-cresol, a substance used as a disinfectant and in the manufacture of several herbicides, is a molecule that contains the elements carbon, hydrogen, and oxygen. Complete combustion of a 0.345-g sample of p-cresol produced 0.983 g carbon dioxide and 0.230 g water. Determine the empirical formula for p-cresol.
Researchers obtained the following data from experiments to find the molecular formula of benzocaine, a local anesthetic, which contains only carbon, hydrogen, nitrogen, and oxygen. Complete combustion of a 3.54-g sample of benzocaine with excess O2 forms 8.49 g CO2 and 2.14 g H2 O. Another 2.35 g sample contains 0.199 g of N. The molar mass of benzocaine is 165 g/mol.Find the molecular formula of benzocaine.
Ferrocene, synthesized in 1951, was the first organic iron compound with Fe⏤C bonds. An understanding of the structure of ferrocene gave rise to new ideas about chemical bonding and led to the preparation of many useful compounds. In the combustion analysis of ferrocene, which contains only Fe, C, and H, a 0.9437-g sample produced 2.233 g of CO2 and 0.457 g of H 2O. What is the empirical formula of ferrocene?
One of the components that make up common table sugar is fructose, a compound that contains only carbon, hydrogen, and oxygen. Complete combustion of 1.50 g of fructose produced 2.20 g of carbon dioxide and 0.900 g of water. What is the empirical formula of fructose?
A compound contains only C, H, and N. Combustion of 35.0 mg of the compound produces 33.5 mg CO2 and 41.1 mg H2O. What is the empirical formula of the compound?
Cumene is a compound containing only carbon and hydrogen that is used in the production of acetone and phenol in the chemical industry. Combustion of 47.6 mg cumene produces some CO2 and 42.8 mg water. The molar mass of cumene is between 115 and 125 g/mol. Determine the empirical and molecular formulas.
A compound contains only carbon, hydrogen, and oxygen. Combustion of 10.68 mg of the compound yields 16.01 mg CO2 and 4.37 mg H2O. The molar mass of the compound is 176.1 g/mol. What are the empirical and molecular formulas of the compound?
Terephthalic acid is an important chemical used in the manufacture of polyesters and plasticizers. It contains only C, H, and O. Combustion of 19.81 mg terephthalic acid produces 41.98 mg CO2 and 6.45 mg H2O. If 0.250 mole of terephthalic acid has a mass of 41.5 g, determine the molecular formula for terephthalic acid.
Isobutylene is a hydrocarbon used in the manufacture of synthetic rubber. When 0.847 g of isobutylene was subjected to combustion analysis, the gain in mass of the CO2 absorber was 2.657 g and that of the H2O absorber was 1.089 g. What is the empirical formula of isobutylene?
The principal component of mothballs is naphthalene, a compound with a molecular mass of about 130 amu, containing only carbon and hydrogen. A 3.000-mg sample of naphthalene burns to give 10.3 mg of CO2. Determine its empirical and molecular formulas.
A 0.025-g sample of a compound composed of boron and hydrogen, with a molecular mass of ~28 amu, burns spontaneously when exposed to air, producing 0.063 g of B2O3. What are the empirical and molecular formulas of the compound?
The combustion of ethane (C2H6) produces carbon dioxide and steam: 2C2H6(g) + 7O2(g) → 4CO2(g) + 6H2O(l) How many moles of CO2 are produced when 5.85 mol of ethane are burned in an excess of oxygen?
In the combustion of hydrogen gas, hydrogen reacts with oxygen from the air to form water vapor. If you burn 33.5 g of hydrogen and produce 299 g of water, how much oxygen reacted?
Be sure to answer all parts. One of the compounds used to increase the octane rating of gasoline is toluene (pictured). Suppose 35.8 mL of toluene (d = 0.867 g/mL) is consumed when a sample of gasoline burns in air. (a) How many grams of oxygen are needed for complete combustion of the toluene? (b) How many total moles of gaseous products form? (c) How many molecules of water vapor form? (Enter your answer in scientific notation.)
Hydrocarbon mixtures are used as fuels. How many grams of CO2(g) are produced by the combustion of 499 g of a mixture that is 25.6% CH4, and 74.4% C3H8 by mass?