Accounting
Anthropology
Archaeology
Art History
Banking
Biology & Life Science
Business
Business Communication
Business Development
Business Ethics
Business Law
Chemistry
Communication
Computer Science
Counseling
Criminal Law
Curriculum & Instruction
Design
Earth Science
Economic
Education
Engineering
Finance
History & Theory
Humanities
Human Resource
International Business
Investments & Securities
Journalism
Law
Management
Marketing
Medicine
Medicine & Health Science
Nursing
Philosophy
Physic
Psychology
Real Estate
Science
Social Science
Sociology
Special Education
Speech
Visual Arts
Physic
Q:
What is the mass of a water molecule, O, in atomic mass units?
A) 2 amu
B) 3 amu
C) 16 amu
D) 18 amu
Q:
What is the mass of an oxygen atom, O, in atomic mass units?
A) 12 amu
B) 16 amu
C) 18 amu
D) 32 amu
Q:
Two amu equals how many grams?
A) 2 grams
B) 1.661 grams
C) 3.322 grams
D) 1.204 grams
Q:
Which has the greatest number of atoms?
A) 28 g of nitrogen, B) 32 g of oxygen, C) 16 g of methane, C
D) 38 g of fluorine,
Q:
Which has the greatest number of molecules?
A) 28 g of nitrogen, B) 32 g of oxygen, C) 32 g of methane, C
D) 38 g of fluorine,
Q:
What is the number of molecules of O2 consumed if you combust one mole of CH4 according to the following balanced equation?CH4 + 2 O2 -> CO2 + 2 H2OA) 1 moleculeB) 2 moleculesC) 6.022 1023 moleculesD) 1.204 024 moleculesE) 1 g of molecules
Q:
What is the number of grams of CO2 produced if you combust 0.50 mole of CH4 according to the following balanced equation?CH4 + 2 O2 -> CO2 + 2 H2OA) 22 gB) 10 gC) 44 gD) 32 gE) 1 g
Q:
What is the number of moles of H2O produced if you combust 0.5 mole of CH4 according to the following balanced equation?CH4 + 2 O2 -> CO2 + 2 H2OA) 2 molesB) 4 molesC) 6 molesD) 8 molesE) 1 mole
Q:
What is the number of moles of H2O produced if you combust one mole of CH4 according to the following balanced equation?CH4 + 2 O2 -> CO2 + 2 H2OA) 2 molesB) 4 molesC) 6 molesD) 8 molesE) 1 mole
Q:
According to the following balanced chemical equation, if you want to generate two moles of H2O how many grams of O2 do you need?2 H2 + O2 -> 2 H2OA) 32B) 16C) 8D) 4E) 6.022 1023
Q:
According to the following balanced chemical equation, if you want to generate two moles of H2O, how many molecules of O2 do you need?2 H2 + O2 -> 2 H2OA) 1B) 2C) 1/2D) 4E) 6.022 1023
Q:
According to the following balanced chemical equation, if you want to generate two moles of H2O, how many moles of O2 do you need?2 H2 + O2 -> 2 H2OA) 1B) 2C) 1/2D) 4E) 6.022 1023
Q:
Which of the following has the greatest mass?
A) 1 mole of Pb
B) 1 mole of H2
C) 1 mole of Be
D) 1 mole of Na
E) All have the same mass.
Q:
Which of the following has the greatest number of particles?
A) 1 mole of Na
B) 22.990 g of Na
C) 1 mole of Be
D) 9.012 g of Be
E) All are the same.
Q:
What is the mass of one mole of H2?
A) 2 g
B) 1 g
C) 20 g
D) 6.022 1023 g
E) none of the above
Q:
How is Avogadro's number related to the numbers on the periodic table?
A) The atomic mass listed is the mass of Avogadro's number's worth of atoms.
B) The masses are all divisible by Avogadro's number, which gives you the weight of one mole.
C) The periodic table tells you the mass of one atom. From that, and Avogadro's number you know the number of moles.
D) The periodic table only gives us atomic numbers, not atomic mass.
E) The mass listed is Avogadro's number.
Q:
How many grams of water can be produced from the combination of 25.0 grams of hydrogen and 225 grams of oxygen?
A) 250 grams
B) 225 grams
C) 200 grams
D) 25 grams
Q:
How many grams of water can be produced by the combination of 8 grams of oxygen and 8 grams of hydrogen?
A) 16 grams
B) 10 grams
C) 9 grams
D) 8 grams
Q:
How many grams of water can be formed from the reaction between 10 grams of oxygen and 1 gram of hydrogen?
A) 11 grams of water are formed since mass must be conserved.
B) 10 grams of water are formed since you can't get a greater mass of water produced than oxygen reacting.
C) 9 grams of water are formed because oxygen and hydrogen react in an 8:1 ratio.
D) No water is formed because there is insufficient hydrogen to react with the oxygen.
Q:
The relative mass of carbon is 3/8 that of an oxygen molecule. How many grams of carbon are needed to have the same number of particles as found in 32 grams of oxygen molecules?
A) 12 g
B) 32 g
C) 3 g
D) 8 g
E) 3/8 g
Q:
What is the formula mass of a molecule of C6H12O6?
A) 180 amu
B) 24 amu
C) 29 amu
D) 168 amu
E) none of the above
Q:
What is the formula mass of a molecule of CO2?
A) 44 amu
B) 56 amu
C) 58.9 amu
D) 118 amu
E) none of the above
Q:
How does formula mass differ from atomic mass?
A) They represent the same thing.
B) The formula mass of a substance is the sum of the atomic masses of the elements is its chemical formula. The atomic mass is the mass of a single atom.
C) The atomic mass of a substance is the sum of the formula masses of the elements is its chemical formula. The atomic mass is the mass of a single atom.
D) The formula mass is the mass of the chemical formula and the atomic mass is the mass of the molecule.
Q:
You are given two samples of elements, and each sample has a mass of 10 grams. If the number of atoms in each of these samples is the same, what must be true of the two elements?
A) The density of the two elements are the same.
B) The elements are likely be located in the same position in the periodic table.
C) Their spectral patterns will likely be identical.
D) all of the above
Q:
Which is greater: 1.01 amu of hydrogen or 1.01 grams of hydrogen?
A) 1.01 amu of hydrogen is greater than 1.01 grams of hydrogen.
B) 1.01 grams of hydrogen is greater than 1.01 amu of hydrogen.
C) 1.01 grams of hydrogen and 1.01 amu of hydrogen have the same mass.
D) Not enough information information is provided.
Q:
Is it possible to have a macroscopic sample of oxygen that has a mass of 14 atomic mass units?
A) Yes, but it would need to be made of oxygen atoms that each had less than the normal number of neutrons.
B) No, this is less than than the mass of a single oxygen atom.
C) Yes, but it would have the same density as nitrogen.
D) No, because oxygen is a gas at room temperature.
Q:
If it takes 20 beryllium atoms to equal the mass of two krypton atoms, what is the relative mass of beryllium compared to krypton?
A) 1/10
B) 1/20
C) 40 times
D) 100 times
E) 10 times
Q:
What are the formula masses of water, O; propene, ; and 2-propanol, O?
A) water: 18 amu; propene: 40 amu; 2-propanol: 58 amu
B) water: 18 amu; propene: 42 amu; 2-propanol: 62 amu
C) water: 18 amu; propene: 42 amu; 2-propanol: 60 amu
D) water: 18 amu; propene: 44 amu; 2-propanol: 64 amu
Q:
If the relative mass of a hydrogen atom is 1/4 that of a helium atom, how many hydrogen atoms would you need to equal the mass of four helium atoms?
A) 16
B) 4
C) 1/4
D) 25
E) 6.022 1023
Q:
If the relative mass of a hydrogen atom is 1/4 that of a helium atom, how many helium atoms would you need to equal the mass of 200 hydrogen atoms?
A) 50
B) 200
C) 800
D) 4
E) 100
Q:
What is the formula mass of sulfur dioxide, S?
A) about 16 amu
B) about 32 amu
C) about 60 amu
D) about 64 amu
Q:
How many oxygen molecules are needed to make 10 carbon dioxide molecules according to the following balanced chemical equation?2 CO + O2 -> 2 CO2A) 5B) 1C) 4D) 10E) 2
Q:
If the relative mass of a pingpong ball is 1/20 that of a golf ball, how many pingpong balls would you need to equal the mass of two golf balls?
A) 40
B) 20
C) 24
D) 100
E) 6.022 1023
Q:
If it takes three carbon atoms to equal the mass of one chlorine atom, what weight of chlorine do you need to equal the number of atoms in one kilogram of carbon?
A) 1/3 of a kg
B) 30 kg
C) 1 kg
D) 3 kg
E) 6 kg
Q:
If it takes three golf balls to equal the mass of one tennis ball, what mass of tennis balls do you need to equal the number of golf balls in one kilogram of golf balls?
A) 1/3 of a kg
B) 30 kg
C) 1 kg
D) 3 kg
E) 6 kg
Q:
If the relative mass of a pingpong ball is 1/20 that of a golf ball, how many golf balls would you need to equal the mass of 200 pingpong balls?
A) 10
B) 200
C) 100
D) 20
E) 6.022 1023
Q:
If it takes 200 golf balls to equal the mass of four bowling balls, what is the relative mass of bowling balls to golf balls?
A) 1/50
B) 1/20
C) 20 times
D) 100 times
E) 6.022 1023
Q:
Why is it important for a chemist to know the relative masses of atoms?
A) There are not that many different kinds of atoms and so it's important to know how they relate to one another.
B) It provides information about how many atoms two samples have relative to each other.
C) It provides an indication of how the different atoms will interact.
D) Because the mass of an atom is directly related to its chemical properties.
Q:
The reactants shown schematically below represent iron oxide, and carbon monoxide, CO. Which of the following is the correct full balanced chemical equation for what is depicted?A) + 3 CO -> 2 Fe + 3 B) + 3 CO -> 3 FeO + 2 CC) + 3 CO -> 3 Fe + 2 CD) + 3 CO -> 2 Fe + 3 O
Q:
Which equation best describes the reaction represented in the illustration above?A) 2 + 2 + -> 2 + 2 B) 2 + 2 + -> 2 + 2 DBAC) 2 + 2 + -> 2 + 2 D) 2 + 2 + -> 2 + 2
Q:
How many diatomic molecules are represented in the illustration above?
A) 1
B) 2
C) 3
D) 4
Q:
Which equations are balanced?a) Mg (s) + 2HCl (aq) -> (aq) + (g)b) 3Al (s) + 3 (l) -> (s)c) 2HgO (s) -> 2 Hg (l) + (g)A) Only equation "c" is balanced.B) Equations "a" and "c" are balanced.C) Equations "b" and "c" are balanced.D) All of them are balanced.
Q:
What coefficient is needed in front of the O2 molecule to balance the following equation?2 (g) + ________ (g) -> 8 (g) + 10 O (l)A) 8B) 13C) 5D) 1
Q:
What coefficients balance the following equation?________ (s) + ________ (g) -> ________ P (g)A) 4, 2, 3B) 1, 6, 4C) 1, 4, 4D) 2, 10, 8
Q:
Balance these equations.________ (g) + ________ (g) -> ________ N (g)A) 2, 2, 3B) 2, 2, 5C) 3, 3, 2D) 3, 1, 2
Q:
Which of the following is a correctly balanced equation?A) P4 + 6 H2 -> 4 PH3B) 1 P4 + 6 H2 -> 4 PH3C) 0 P4 + 6 H2 -> 4 PH3D) 2 P4 + 12 H2 -> 8 PH3E) P4 + 3 H2 -> PH3
Q:
Balance the following equation.________ NO -> ________ N2O + ________ NO2A) 3, 1, 1B) 3, 0, 0C) 4, 4, 8D) 1, 2, 4E) 6, 2, 1
Q:
Balance the following chemical equation.________ N2 + ________ H2 -> ________ NH3A) 1, 3, 2B) 1, 2, 3C) 3, 2, 1D) 2, 6, 4E) 1/2, 3/2, 1
Q:
For the following balanced equation, which has the highest coefficient?4 H2 + 2 C -> 2 CH4A) H2B) CC) CH4D) H4E) none of the above
Q:
For the following balanced reaction, which of the following is a gas?2 Na(l) + Cl2(g) -> 2 NaCl(s)A) NaB) 2 NaC) Cl2D) ClE) NaCl
Q:
For the following balanced reaction, which of the following is a solid?2 Na(l) + Cl2(g) -> 2 NaCl(s)A) NaB) 2 NaC) Cl2D) ClE) NaCl
Q:
Given the following generic chemical reaction, which is the reactant?X -> YA) Y is the reactant.B) X is the reactant.C) -> is the reactant.D) Both X and Y are the products.E) Both X and Y are the reactants.
Q:
Given the following generic chemical reaction, which is the product?X -> YA) Y is the product.B) X is the product.C) -> is the product.D) Both X and Y are the products.E) Both X and Y are the reactants.
Q:
What is a chemical equation?
A) It is a shorthand notation for illustrating a chemical reaction.
B) It is the sum of the masses of the products and reactants.
C) It is the chemical combination of equal numbers of reactants and products.
D) It is a picture of the atoms undergoing a chemical equalization.
E) It is any type of reaction that takes place at the equator.
Q:
What is a chemical reaction?
A) when one or more new compounds are formed by rearranging atoms
B) when a new element is formed by rearranging nucleons
C) when two solids mix together to form a heterogeneous mixture
D) when two liquids mix to form a homogeneous mixture
E) when a liquid undergoes a phase change and produces a solid
Q:
What is wrong with the following depiction of a chemical reaction? A) These boxes contain only molecules but no atoms.
B) One box contains more molecules than the other.
C) One box contains more atoms than the other.
D) All of the above.
Q:
A friend argues that if mass were really conserved he would never need to refill his gas tank. What explanation do you offer your friend?
A) The atoms (mass) of gasoline are converted into energy by the engine according to E=m.
B) The Law of Conservation of Mass does not apply to reactions involving combustion or explosion of matter.
C) The atoms (mass) of gasoline are converted into exhaust fumes.
D) The oil companies make gasoline in a way that it gets used up so that we are always required to replenish it.
Q:
Steel wool wetted with vinegar is sealed within a balloon inflated with air. After several hours, what happens to the volume of the balloon?
A) The balloon inflates.
B) The balloon deflates.
C) The balloon dissolves.
D) Nothing because the vinegar is acting on the steel wool, not upon the balloon.
Q:
Steel wool wetted with vinegar is stuffed into a narrow mouth round glass bottle. A rubber balloon is then sealed over the mouth of the bottle. After several hours, the balloon inflates into the bottle in an inverted manner. What happened?
A) Vinegar fumes are diamagnetic and as they accumulate above the liquid the steel wool is attracted thus inflating the balloon into the mouth of the bottle in an inverted manner.
B) The caustic vinegar fumes get past the steel wool and deteriorate the balloon, which begins to sag into the bottle and inflate it in an inverted manner.
C) The vinegar reacts with the steel wool by absorbing oxygen within the bottle thus decreasing the pressure. The greater outside pressure causes the balloon to inflate in an inverted manner.
D) False! The balloon inflates above the mouth of the bottle because the reaction between the vinegar and steel wool produces a gas which is forced upward because of increased pressure inside the sealed bottle.
Q:
The concept of entropy tells us how exothermic reactions are
A) favored over endothermic reactions.
B) not as favorable as endothermic reactions.
C) just as effective as endothermic reactions.
D) the reverse of endothermic reactions.
Q:
Entropy helps to explain
A) the forward motion of time.
B) the cause of a chemical reaction.
C) sunsets.
D) photosynthesis.
E) All of the above.
Q:
Wild plants readily grow "all by themselves" yet the molecules of the growing plant have less entropy than the materials used to make the plant. How is it possible for a there to be this decrease in entropy for a process that occurs all by itself?
A) A decrease in entropy does not necessarily mean that a reaction if favored to proceed on its own. It happens in this instance but not in others.
B) There is no decrease in entropy when wild plants grow. All growing plants tend to display an increase in entropy.
C) Wild plants don't grow "all by themselves." When we consider the entire system, including the sun, we find an overall increase in entropy.
D) Life on Earth "arises on its own." It does not depend on entropy processes.
Q:
Why does iodine, (s), spontaneously sublime at room temperature?
A) The contact of iodine, (s), with the water vapor in the air causes the sublimation process.
B) Iodine, (s), pulls from the air as it self-oxidizes under sublimation to (g).
C) There is an increase in entropy as solid iodine, (s), sublimes into iodine vapor, (g), because in the gaseous phase energy is more readily dispersed.
D) The reaction of (s) subliming to (g) is highly exothermic and therefore proceeds spontaneously.
Q:
What role does entropy play in chemical reactions?
A) The entropy determines how much product will actually be produced.
B) The entropy change determines whether the reaction will be exothermic or endothermic.
C) The entropy change determines whether the reaction will occur spontaneously or not.
D) The entropy change determines whether or not the chemical reaction is favorable.
Q:
Which of the following statements best describes the concept of entropy?
A) Energy has a tendency to disperse.
B) Energy is neither created nor destroyed.
C) The entropy of the universe is constantly decreasing.
D) The energy released in a chemical reaction is the same as the difference in the energy of the bonds broken and formed.
E) Energy has a tendency to remain in one place.
Q:
How much energy, in kilojoules, is released or absorbed from the reaction of one mole of nitrogen, , with three moles of molecular hydrogen, , to form two moles of ammonia, N?H-N (bond energy: 389 kJ/mol)H-H (bond energy: 436 kJ/mol)NN (bond energy: 946 kJ/mol)NN + H-H + H-H -> N + NA) +899 kJ/mol absorbedB) -993 kJ/mol releasedC) +80 kJ/mol absorbedD) -80 kj/mol released
Q:
Use the bond energies below to determine whether the following reaction is exothermic or endothermic:+ -> 2 HClH-H (bond energy: 436 kJ/mol)Cl-Cl (bond energy: 243 kJ/mol)H-Cl (bond energy: 431 kJ/mol)A) Exothermic with more than 50 kJ of energy released.B) Endothermic with more than 50 kJ of energy absorbed.C) Exothermic with less than 50 kJ of energy released.D) Endothermic with less than 50 kJ of energy absorbed.
Q:
Are the chemical reactions that take place in a disposable battery exothermic or endothermic? Is the reaction going on in a rechargeable battery while it is recharging exothermic or endothermic?
A) An operating disposable battery is driven by endothermic reaction, while a recharging rechargeable battery is also driven by endothermic reactions.
B) An operating disposable battery is driven by exothermic reaction, while a recharging rechargeable battery is driven by endothermic reactions.
C) An operating disposable battery is driven by endothermic reaction, while a recharging rechargeable battery is driven by exothermic reactions.
D) An operating disposable battery is driven by exothermic reaction, while a recharging rechargeable battery is also driven by exothermic reactions.
Q:
Bond energies increase in going from C-N (lowest) to C-O to C-F (highest). Explain this trend based upon the atomic sizes of these atoms as deduced from their positions in the periodic table.
A) In going from nitrogen to oxygen to fluorine the atoms get larger. This means a greater nuclear charge, which translates into stronger chemical bonds.
B) In going from nitrogen to oxygen to fluorine the atoms get smaller. This means a greater nuclear charge, which translates into stronger chemical bonds.
C) In going from nitrogen to oxygen to fluorine the atoms get larger. This means that the bonding atoms are farther apart, which translates into a greater bond energy.
D) In going from nitrogen to oxygen to fluorine the atoms get smaller. This means that the bonding atoms are closer together, which translates into a greater bond energy.
Q:
Which is higher in an endothermic reaction: the potential energy of the reactants or the potential energy of the products?
A) The potential energy of the products is higher than the potential energy of the reactants.
B) The potential energy of the reactants is higher than the potential energy of the products.
C) The potential energy of the reactants is the same as the potential energy of the products.
D) In the early stages of the reaction the potential energy of the reactants is higher. In the later stages, the potential energy of the products is higher.
Q:
Which of the following reaction energies is the most endothermic?
A) 540 kJ/mole
B) -540 kJ/mole
C) 125 kj/mole
D) -125 kJ/mole
E) not enough information given
Q:
Which of the following reaction energies is the least exothermic (but still an exothermic reaction)?
A) 540 kJ/mole
B) -540 kJ/mole
C) 125 kJ/mole
D) -125 kJ/mole
E) not enough information given
Q:
Given that the bond energy of N2 is 946 kJ/mole, the bond energy of O2 is 498 kJ/mole and the NO bond energy is 631 kJ/mole, how much energy is required to react 1 mole of nitrogen molecules according to the following reaction?N2 + O2 -> 2 NOA) 182 kJB) -182 kJC) 813 kJD) -813 kJE) 2075 kJ
Q:
How many moles of H2 bonds are broken if you react nitrogen with hydrogen according to the following reaction?N2 + 3H2 -> 2 NH3A) 6B) 2C) 3D) 1E) 8
Q:
How many bonds between nitrogen and hydrogen are formed if you react nitrogen with hydrogen according to the following reaction?N2 + 3H2 -> 2 NH3A) 6B) 2C) 3D) 1E) 8
Q:
R = reactants P = products
Given that the above energy profiles have the same scale, which of the reactions would require the most energy?
A) a
B) b
C) c
D) d
E) none of the above
Q:
R = reactants P = products
Given that the above energy profiles have the same scale, which of the reactions is the most exothermic?
A) a
B) b
C) c
D) d
E) none of the above
Q:
Given the following energy profiles, which of the following reactions is endothermic? R= reactants P = products
A) a
B) b
C) c
D) d
E) none of the above
Q:
If it takes energy to break bonds and you gain energy in the formation of bonds, how can some reactions be exothermic while others are endothermic?
A) It is the total amount of energy that matters. Sometimes some bonds are stronger than others and so you gain or lose energy when you form them.
B) It is the total number of bonds that matters. Sometimes you create more bonds than you break and since all bonds have same amount of energy you gain or lose energy depending on the number of bonds.
C) Some reactants have more energetic bonds than others and they will always release energy.
D) Some products have more energy than others and they always require energy to be formed.
E) none of the above
Q:
What is an endothermic reaction?
A) It is a reaction that requires heat as a reactant.
B) It is a reaction where the products have more energy than the reactants.
C) It is a reaction where there is a net adsorption of energy from a reaction.
D) all of the above
E) none of the above