moles/stoichiometry

	moles/stoichiometry.....aims

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determine the molecular formula, given the empirical formula and molecular mass
determine the empirical formula from a molecular formula
calculate the formula mass and the gram-formula mass
determine the number of moles of a substance, given its mass
determine the mass of a given number of moles of a substance
balance equations, given the formulas for reactants and products
interpret balanced chemical equations in terms of conservation of matter and energy
create and use models of particles to demonstrate balanced equations
calculate simple mole-mole stoichiometry problems, given a balanced equation
identify types of chemical reactions

real-world connections

reading food and beverage labels (consumer Chemistry)
recovery of metals from ores
electroplating
corrosion
precipitation reactions
dangers of mixing household chemicals together, e.g., bleach and ammonia
electrolysis of active metal compounds
explosives (inflation of air bags)

fill-in the blanks

Words: actual, balanced, broken, coefficients, conservation, empirical, fixed, formula, IUPAC, molar, percent, synthesis, whole-number

A compound is a substance composed of two or more different elements that are chemically combined in a ______ proportion. A chemical compound can be _______ down by chemical means. A chemical compound can be represented by a specific chemical formula and assigned a name based on the _______ system. Types of chemical formulas include _________, molecular, and structural. The empirical formula of a compound is the simplest ______- _________ ratio of atoms of the elements in a compound. It may be different from the molecular formula, which is the ______ ratio of atoms in a molecule of that compound. In all chemical reactions there is a __________ of mass, energy, and charge. A ________ chemical equation represents conservation of atoms. The __________ in a balanced chemical equation can be used to determine mole ratios in the reaction. The _________ mass of a substance is the sum of the atomic masses of its atoms. The ________ mass (gram-formula mass) of a substance equals one mole of that substance. The ________ composition by mass of each element in a compound can be calculated mathematically. Types of chemical reactions include ________, decomposition, single replacement, and double replacement.

quiz 1

Question #1
What is a compound composed of?
[A] two or more different elements that are physically combined in a fixed proportion
[B] two or more different mixtures that are physically combined in a fixed proportion
[C] two or more different elements that are chemically combined in a fixed proportion
[D] two or more different elements that are chemically combined in a variable proportion

Question #2
How can a chemical compound be broken?
[A] can be broken down by physical means
[B] can be broken down by chemical means
[C] cannot be broken down
[D] can be broken down by physical or chemical means

Question #3
A chemical compound can be represented by a specific chemical formula and assigned a name based on the IUPOC system.
True
False

Question #4
The stock system is used for naming any ionic compounds.
True
False

Question #5
What is the name of CaCl2?
[A] calcium dichloride
[B] calcium (II) chloride
[C] monocalcium dichloride
[D] calcium chloride

Question #6
What is the name of Mg(NO3)2
[A] Magnesium nitrate
[B] Magnesium (II) nitrate
[C] Magnesium dinitrate
[D] Magnesium nitrogen oxide

Question #7
What is the name of P2O5?
[A] phosphorus oxide
[B] phosphorus pentaoxide
[C] diphosphorus pentaoxide
[D] phosphorus (III) oxide

Question #8
What is the formula for sulfur hexachloride?
[A] S5Cl
[B] SHCl
[C] SCl5
[D] SCl6

Question #9
What is the name of the formula Fe(NO3)2?
[A] iron nitrate
[B] iron (II) nitrate
[C] iron dinitrate
[D] iron (III) nitrate

Question #10
What is the formula for the compound nitrogen (II) oxide.
[A] N2O3
[B] NO
[C] NO2
[D] N2O

quiz 2

Question #1
Which of the following is not a type of chemical formula?
[A] Empirical
[B] Molecular
[C] Structural
[D] parabola

Question #2
The molecular formula of a compound is the actual ratio of atoms in a molecule of that compound
True
False

Question #3
Empirical formula of a compound is the actual ratio of atoms in a molecule of that compound.
True
False

Question #4
What is the structural formula of a compound?
[A] the arrangement of atoms in a molecule of that compound
[B] the actual ratio of atoms in a molecule of that compound
[C] the simplest ratio of atoms in a molecule of that compound
[D] the Lewis-dot structure of atoms in a molecule of that compound

Question #5
What is the formula mass of a substance?
[A] the sum of the first ionization energies of its atoms
[B] the sum of the atomic numbers of its atoms
[C] the sum of the atomic masses of its atoms
[D] the sum of electronegativities of its atoms

Question #6
Which of the following of a substance does not equal to one mole of that substance?
[A] molar mass
[B] gram-formula mass
[C] atomic mass
[D] none of the above

Question #7
Which of the following can be an empirical formula?
[A] C6H6
[B] C3H6
[C] CH4
[D] C10H22

Question #8
What is the molar mass of a carbonate ion?
[A] 30
[B] 60
[C] 90
[D] 120

Question #9
The molecular formula of a compound is represented by X3Y6Z9. What is the empirical formula of this compound?
[A] X2Y5Z8
[B] X2Y4Z6
[C] XY4Z7
[D] XY2Z3

Question #10
Which substance has the least molecular mass?
[A] H2O
[B] CH4
[C] NO
[D] NaCl

quiz 3

Question #1
Which statement best describes the conservation of atoms in all balanced chemical equations?
[A] There is a conservation of mass, number of protons, and charge.
[B] There is a conservation of mass, electronegativity, and charge.
[C] There is a conservation of only energy, and charge.
[D] There is a conservation of mass, energy, and charge.

Question #2
Given the unbalanced equation ; CuS + O2 -> CuO + SO2 When it is balanced, what is the sum of the coefficients?
[A] 8
[B] 9
[C] 10
[D] 11

Question #3
Which one of these chemical reactions is balanced?
[A] Na + Cl2 -> NaCl
[B] H2 + O2 -> H2O
[C] CuCO3 -> CuO + CO2
[D] KClO3-> KCl + O2

Question #4
Which is the correct way of setting up a word equation for this balanced chemical equation, 2Na + Cl2 -> 2NaCl?
[A] Sodium react with chlorine gas to produce sodium chloride.
[B] 2 moles of sodium react with 1 mole of chlorine to yield 1 mole of sodium chloride.
[C] 2 moles of sodium react with 1 mole of chlorine gas to yield 2 mole of sodium chloride.
[D] 2 moles of sodium added with 1 mole of chlorine gas to yield 1 mole of sodium chloride.

Question #5
2 moles of copper react with 1 mole of oxygen gas to yield 2 moles of copper (ll) oxide. How would you express this word equation into a balanced chemical equation?
[A] Cu + O -> CuO
[B] Cu + O2 -> CuO
[C] 2Cu + O -> CuO
[D] 2Cu + O2 -> 2CuO

Question #6
The coefficients in a balanced chemical equation can be used to determine mole ratios in the reaction.
True
False

Question #7
Consider the balanced equation Zn + 2HCl -> ZnCl2 + H2 How many moles of ZnCl2 will be produced if 7 moles of HCl are used?
[A] 2 moles
[B] 2.5 moles
[C] 3.5 moles
[D] 4 moles

Question #8
Given : C2H2(g) + 5O2(g) -> 4CO2(g) + 2H2O(g) Is this chemical equation balanced?
True
False

Question #9
In the reaction below, how many moles of oxygen gas is produced by the decomposition of 4 moles of mercury (II) oxide? 2HgO -> 2Hg + O2
[A] 1 mole
[B] 2 moles
[C] 3 moles
[D] 4 moles

Question #10
6 moles of H2 is needed to completely react with 2 moles of N2 in the balanced chemical reaction N2 + 3H2 -> 2NH3
True
False

quiz 4

Question #1
The percent composition by mass of each element in a compound can be calculated mathematically, using the mole calculation formula.
True
False

Question #2
The percent by mass of iodine in KI is approximately
[A] 77%
[B] 50%
[C] 80%
[D] 36%

Question #3
The percent by mass of chlorine in SCl4 is approximately
[A] 62%
[B] 98%
[C] 81%
[D] 25%

Question #4
What is the percent by mass of calcium in CaSO4.2H20?
[A] 32%
[B] 23%
[C] 51%
[D] 84%

Question #5
What is the percent by mass of iron in Iron (III) oxide?
[A] 60%
[B] 40%
[C] 30%
[D] 70%

Question #6
What is the gram formula mass of sodium hydrogen carbonate?
[A] 100g
[B] 48g
[C] 84g
[D] 95g

Question #7
What is the percent by mass of rubidium in Rb2O?
[A] 70%
[B] 99%
[C] 43%
[D] 91%

Question #8
The percent composition by mass of each element in a compound
[A] can be calculated scientifically
[B] can not be calculated
[C] can be calculated mathematically
[D] is a fact

Question #9
What is the percent by mass of Boron in BF3?
[A] 10%
[B] 20%
[C] 18%
[D] 16%

Question #10
What is the percent by mass of sodium in Na2O?
[A] 72%
[B] 74%
[C] 76%
[D] 78%

quiz 5

Question #1
What are the different types of chemical reactions?
[A] synthesis, fusion, combustion, fission, and decomposition
[B] single replacement, combustion, and double replacement
[C] synthesis, fission, single replacement, combustion, and fusion
[D] synthesis, decomposition, combustion, single and double replacement

Question #2
What type of reaction is represented by 2 or more elements forming a compound?
[A] Decomposition
[B] Synthesis
[C] Combustion
[D] Single replacement

Question #3
Decomposition is the burning of hydrocarbons in the presence of oxygen.
True
False

Question #4
Which of the following general equations represents a single replacement reaction?
[A] x + yA -> xA + y
[B] xA + yB -> yA + xB
[C] A + B -> C
[D] C -> A + B

Question #5
Which equation represents a double replacement reaction?
[A] CaCO3 -> CaO + CO2
[B] CH4 + 2O2 -> CO2 + 2
[C] LiOH + HCl -> LiCl + H20
[D] C3H8 + 5O2 -> 3CO2 + 8H20

Question #6
What chemical reaction has the products carbon dioxide and water?
[A] Combustion
[B] Synthesis
[C] Decomposition
[D] None of the above

Question #7
MgSO4 + BaCl2 --> MgCl2 + BaSO4, is an example of what type of chemical reaction?
[A] single replacement
[B] synthesis
[C] combustion
[D] double replacement

Question #8
Zn + 2 AgNO3 --> 2 Ag + Zn(NO3)2, is an example of what type of chemical reaction?
[A] Synthesis
[B] Single replacement
[C] Decomposition
[D] Double replacement

Question #9
The cation of one compound replaces the cation in another compound in a double replacement reaction.
True
False

Question #10
Which equation represents combustion?
[A] 4 Fe + 3 O2 --> 2 Fe2O3
[B] 2H2O --> 2H2 + O2
[C] CH4 + 2O2 --> CO2 + 2 H2O
[D] Cu + 2 AgNO3 --> Cu(NO3)2 + 2 Ag

quiz 6

Question #1
Which of these compounds are soluble in water?
[A] CaBr2
[B] PbCl2
[C] SrS
[D] CaCO3

Question #2
Which of these compounds is insoluble in water?
[A] CuI
[B] CaCl2
[C] MgS
[D] NaBr

Question #3
Iron (III) sulfide is soluble in water.
True
False

Question #4
According to reference table F, which of these salts is not soluble in water?
[A] NH4NO3
[B] AlPO4
[C] FeSO4
[D] K2S

Question #5
LiBr is
[A] soluble
[B] insoluble
[C] can't tell the solubility
[D] a covalent compound

Question #6
NH4OH is insoluble.
True
False

Question #7
Which of these compounds is soluble?
[A] Pb(OH)4
[B] NaHCO3
[C] BaCrO4
[D] Mg3(PO4)2

Question #8
Which compound are you not able to predict the solubility when using table F?
[A] (NH4)2CO3
[B] UF6
[C] Na2CO3
[D] SrI2

Question #9
Is KClO3 soluble?
True
False

Question #10
Predict the solubility of the 3 following compounds:
Sn(NO3)2, Ni(C2H3O2)2, and Cu(ClO3)2
[A] Insoluble, Soluble, Insoluble
[B] Insoluble, Insoluble, Insoluble
[C] Soluble, Soluble, Soluble
[D] Soluble, Insoluble, Soluble

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