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Combustion, Stoichiometry
Related Topics
Wize University Chemistry Textbook > Stoichiometry
Atoms, Molecules, and the Mole!
4 Activities
Wize University Chemistry Textbook > Stoichiometry
Combustion Reactions + Empirical and Molecular Formulae
4 Activities
What mass of KClO
3
is required to produce proper amount of O
2
needed to achieve complete combustion of 78.88 g CH
4
?
2 KClO
3
→ 2 KCl + 3 O
2
975.7 g
100.0 g
803.6 g
204.5 g
I don't know
Check Submission
More Atoms, Molecules, and the Mole! Questions:
Given that the molar mass of X is 170.12 g mol
-1
, how many molecules of X are present in a tablet that contains 100 mg of X?
Calculate the molar mass of H
2
O
Chemical reactions: Limiting Reagent & Percent Yield
Iron oxidizes when exposed to oxygen to form iron oxide according to the following equation:
Fe (s) + O
2
(g) → Fe
2
O
3
(s)
352g of pure iron is exposed to 12.0 mols of O
2
, and after a period of time, 46.7 g of iron oxide (rust) is collected.
Molecules: Molar mass
Calculate the number of moles of each compound:
a. 18.5 g of MgCO
3
b. 2.36 g of NF
3
Stoichiometry: Chemical formula
How many carbon atoms are in 10.00 mL of ethanol ( CH
3
CH
2
OH)?
The density of ethanol is 0.789 g/mL.
Practice: Finding the Number of Moles of Iron
Calculate the number of moles of Iron atoms in 14.1 g of iron oxide, Fe
2
O
3
Introduction to General Chemistry
Answer the following questions concerning benzoic acid (C
7
H
6
O
2
).
a)
Calculate the number of moles in a 7.50 x 10
-2
g sample of benzoic acid.
b)
Calculate the number of molecules of benzoic acid in the 7.50 x 10
-2
g sample.
Stoichiometry: Moles, atomic mass
Acetominophen (C
8
H
9
NO
2
) is a common drug used to treat pain and fever. It is the main component of common trade names such as Tylenol.
a)
Calculate the molar mass of acetominophen.
b)
How many moles of acetominophen are there in 250.0 g of this compound?
Converting Mass to Number of Atoms
Calculate the number of nitrogen atoms in 2.25 g of bismuth(III) nitrate. (Enter your answer in scientific notation in nitrogen atoms, for example
1.23
⋅
10
18
1.23\cdot10^{18}
1.23
⋅
1
0
18
)
How many grams of oxygen are in 22 mL of water? Remember that the density of water is 1.0 g/mL
How many moles of ammonia (NH
3
) are in 2.4g of ammonia?
Chemical formula: Moles
Which of the following quantities is not equivalent to 5 mg of sodium bicarbonate,NaHCO
3
?
Stoichiometry: Finding the Number of Moles of Iron
Calculate the number of moles of iron atoms in 14.1 g of iron oxide, Fe
2
O
3
Atoms: Avogadro's Number
How many
C
\text{C}
C
atoms are there in 260 g of
H
2
CO
3
\text{H}_2\text{CO}_3
H
2
CO
3
?
Stoichiometry: Molar mass and Avogadro's Number
How many hydrogen atoms are in exactly 2 g of hydrazinium sulfate, N
2
H
6
SO
4
?
More Combustion Reactions + Empirical and Molecular Formulae Questions:
Empirical formula: Combustion reaction
When 2.11 g of an unknown hydrocarbon (compound made up of only carbon and hydrogen atoms) was burned in excess oxygen as part of a combustion analysis. In the process 6.32 g of CO
2
and 3.45 g of H
2
O are produced. What is the mass percent of carbon? What is the empirical formula of the hydrocarbon?
Empirical Formula
A 1.00 g sample of a species containing only C, H, and O was completely combusted in pure oxygen, and 1.5 g CO
2
and 0.41g H
2
O were obtained. What is the empirical formula of the compound?
Combustion and Empirical Formula
A hydrocarbon (0.875 g) containing only C, H, and O yielded 2.21 g CO
2
and 0.387 g H
2
O after complete combustion.
What is the empirical formula?
Combustion Analysis Calculation
When 2.11 g of an unknown hydrocarbon (compound made up of only carbon and hydrogen atoms) was burned in excess oxygen as part of a combustion analysis. In the process 6.32 g of CO
2
and 3.45 g of H
2
O are produced. What is the empirical formula of the hydrocarbon?
Stoichiometry 2
An unknown hydrocarbon contains 40.0% C and 6.66% H by weight.
a. What is the empirical formula of the compound?
b. What is the molecular formula if molecular weight of the compound is 180 gmol
-1
?
Gas stoichiometry and Empirical Formula
Complete combustion of a hydrocarbon yields 1.5 L CO
2
and 2 L H
2
O at 298 K and 101 kPa. Whats the empirical formula of the compound?
Empirical Formula
A 1.00 g sample of a species containing only C, H, and O was completely combusted in pure oxygen, and 1.5 g CO
2
and 0.41g H
2
O were obtained. What is the empirical formula of the compound? (enter answer: C_H_O_ For example C2H2O5)
Empirical Formulae
This question focuses on material from 1.3. Empirical Formulae.
Empirical Formulae
3.0 g of an organic compound, C
x
H
y
O
z
, is combusted in air to produce 7.75 g of carbon dioxide and 3.70 g of water vapour. Determine the empirical formula of this compound.
Empirical Formulae
An organic compound, C
x
H
y
Cl
z
, was subject to elemental analysis, and the compound was found to contain 64.6% carbon by mass and 11.5% hydrogen by mass. Determine the empirical formula of this compound.
Mass Percentage Practice
0.2976g of an unknown compound gives 0.3147g of CO2 and 0.3026g of H2O on combustion. The only other element known to be present is N. What is the empirical formula?
Empirical Formulae
5.
5.0 g of an organic compound, C
x
H
y
O
z
, is combusted in air to produce 11.87 g of carbon dioxide and 6.08 g of water vapour. Determine the empirical formula of this compound.
Empirical formula: Combustion reaction
When 2.11 g of an unknown hydrocarbon (compound made up of only carbon and hydrogen atoms) was burned in excess oxygen as part of a combustion analysis. In the process 6.32 g of CO
2
and 3.45 g of H
2
O are produced. What is the empirical formula of the hydrocarbon?
Combustion Analysis
For a hydrocarbon (a molecule made up of only C and H atoms) combustion analysis allows us to determine the: