General Questions and Answers
Physical Chemistry
GeneralThe strong nuclear force has several properties that determine its effect on atomic particles including all of the following EXCEPT
it is only attractive, never repulsive.
It acts on both charged and neutral particles.
It is a short-range force.
It acts upon protons, neutrons, and electrons to hold the nucleus together.
Physical Chemistry
GeneralYou may want to reference (Page) Section 11.8
while completing this problem.
When heated to 350 °C at 0.950 atm, ammonium
nitrate decomposes to produce nitrogen, water, and
oxygen gases via the following reaction:
2NH4NO3 (s) 2N2₂ (g) + 4H₂O(g) + O2(g)
Part A
How many liters of water vapor are produced when 25.3 g of NH4NO3 decomposes?
Express your answer with the appropriate units.
V =
Part B
How many grams of NH4NO3 are needed to produce 16.8 L of oxygen?
Express your answer with the appropriate units.
Physical Chemistry
GeneralWhat evidence is there to support the theory that strong nuclear force is greater than electromagnetic force?
Electrons are attracted to protons.
Protons repel other protons.
The nucleus holds the protons together.
Protons and neutrons are attracted to each other.
Physical Chemistry
GeneralWhich of the following statements about entropy and spontaneity of the process of rusting are True?
4 Fe(s) +302(g) 2 Fe2O3(s)
□ (a) ΔSsys= (-); ASsurr = (-); ASuniv = (+)
□ (b) ΔSuniv = (-), identifies this as a spontaneous process.
□ (c) ΔGO for this reaction must be negative.
□ (d)O2(g) from the air reacts with Fe(s) on the surface of the car, which decreases the entropy of the system.
□ (e) ΔSsys = (-); ΔSsurr = (+); ΔSuniv = (+)
Select all possible options that apply.
Physical Chemistry
GeneralConsider the fo ving reaction and assume that 20.0 g of NaH (molar mass: 24.00 g/mol) was mixed with 20.0 g of BC13 (molar mass: 117.17 g/mol) to produce B₂H6 (molar mass: 27.66 g/mol) as a target product. Answer the following questions.
6 NaH+8BCl3 → 6NaBCl4 + B₂H6
A. Determine which one of the two reactants will be a limiting agent. (6 pt)
B. Calculate how many grams of the excess reactant will remain after the reaction is completed.
C. Calculate the theoretical yield of B₂H, in the unit of g. (4 pt)
D. If the actual yield of B₂H6 was 0.42 g, what is the % yield of this reaction? (2 pt)
Physical Chemistry
GeneralMethanol (CH₂OH) can be produced by the reaction of carbon monoxide (CO) with hydrogen (H₂). The balanced chemical reaction is
CO(g) + 2 H₂(g) → CH₂OH()
a. If 21.409 g of carbon monoxide is reacted with 3.377 g of hydrogen a Which reactant is the limiting reactant?
CO(g) H₂(g)
b. What mass is the theoretical yield for methanol?
Report the mass value in grams to the nearest 0.001 g. Do not enter the unit
c. At the completion of the reaction, what mass of the excess reactant will remain?
Report the mass value in grams to the nearest 0.001 g. Do not enter the unit.
Physical Chemistry
GeneralIn the narrative, Tom lures his friends into whitewashing the fence, while he enjoys
with the things he gets in exchange. Which of the following phrases describes how
more of his friends became victims?
alacrity in his heart
with reluctance in his face
the slaughter of more innocents
Physical Chemistry
GeneralCalculate the volume (mL) of 1.0 M potassium carbonate (K₂CO3) needed to prepare 5.0 g of the COBALT pigment. This is where the balanced chemical equation comes in. You should be able to relate the moles of pigment to the moles of K₂CO3, and from that calculate the volume of 1.0 M K₂CO3 solution needed. Please report your value as XX.X mL (one decimal point and no units).
Physical Chemistry
GeneralIron(III) oxide (Fe₂O₂) can be converted into irop metal (Fe) by a reaction with carbon (C) where the other product is carbon dioxide (CO₂). The balanced chemical reaction is
2 Fe₂O3(s) + 3 C(s)→ 4 Fe(s) + 3 CO₂(g)
If 4 moles of iron(III) oxide is reacted
a. How many moles of carbon are needed to react with the iron oxide with no amount of either reactant left over?
b. How many moles of iron will be produced?
c. How many moles of carbon dioxide will be produced?
Physical Chemistry
GeneralA powder contains FeSO4.7H₂O (molar mass = 278.01 g/mol), among other components. A 3.360 g sample of the powder was dissolved in HNO, and heated to convert all iron to Fe³+. The addition of NH, precipitated Fe₂O3. xH₂O, which was subsequently ignited to produce 0.627 g Fe₂O3.
What was the mass of FeSO4 7 H₂O in the 3.360 g sample?
mass of FeSO4.7H₂O: BO
Physical Chemistry
General2. Write chemical equations that represent these word equations:
a. Baking soda (NaHCO3) reacts with hydrochloric acid (HCl) to produce sodium chloride, water, and carbon dioxide.
b. During respiration, one molecule of glucose (C,H₁2O6) reacts with six molecules of oxygen gas to produce six molecules of carbon dioxide and six molecules of water.
Physical Chemistry
GeneralRead the following lines and identify the style of writing.
"Edward Everett Hale(1822-1909) is chiefly known as the author of the short story,
The Man Without a Country (December 1863, Atlantic Monthly), but his venture in
the comic vein, My Double; and How He Undid me (September 1859, Atlantic
Monthly), is equally worthy of appreciation."
Source: https://www.gutenberg.org/files/10947/10947-h/10947-h.htm
Informative
Descriptive
Narrative
Physical Chemistry
GeneralFor the following reaction, 15.2 grams of carbon monoxide are allowed to react with 7.05 grams of water.
carbon monoxide(g) + water(1) ⇒ carbon dioxide(g) + hydrogen(g)
What is the maximum amount of carbon dioxide that can be formed?
What is the FORMULA for the limiting reagent?
What amount of the excess reagent remains after the reaction is complete?
Physical Chemistry
GeneralWhich of the following statements is/are correct?
Hydrocarbons are covalent hydrides
Covalent hydrides does not conduct heat and electricity
lonic hydrides do not conduct electricity in solid state.
lonic hydrides are very good conductors of electricity in solid state
Physical Chemistry
GeneralWhat is the molarity of a solution composed of 8.2 g of potassium chromate, K₂CrO4 dissolved in enough water to make 500. mL of solution?? (Hint: need to change the grams of the solute to mole before putting into the Molarity equation.)
Physical Chemistry
GeneralGay-Lussac's law states that the pressure of a gas is directly related to its absolute temperature, provided the volume and number of moles of the gas remain the
same: (Figure 1)
P1/T1=P2/T2
In an ideal gas, particles are considered to interact only when they collide, with no loss in energy or speed occurring during the collision. Studying ideal gases
allows for simplifications, such as Gay-Lussac's law.
A sample of a gas is in a sealed container. The pressure of the gas is 365 torr, and the temperature is 1 °C. If the temperature changes to 62 °C with no change in volume or amount of gas, what is the new pressure, P2, of the gas inside the container?
Physical Chemistry
GeneralIron changes oxidation state during the course of this experiment. The iron oxalate (step 1 product) has iron in an oxidation state of trihydrate has iron in an oxidation state of and the product potassium tris(oxalate) ferrate
Physical Chemistry
GeneralWhat is the role of a conclusion in a story?
It should provide nothing other than a moral.
It will have to provide a happy ending.
It has to tie up all the loose ends created in the story.
Physical Chemistry
GeneralThe enantiomeric excess and observed specific rotation of a mixture containing 6 g of (+)-2- butanol and 4(g) of (-)-2-butanol are respectively. (If the specific rotation of enantiomerically pure(+)-2-butanol is +13.5 units)
A 80%, +2.7 unit
B 20%, -2.7 unit
C 20%, +2.7 unit
D 80%, -27 unit
Physical Chemistry
GeneralWhich of the following statements about the conformations of acyclic alkanes is true?
In the staggered conformation, the C-H bonds on one carbon are directly aligned with the C-H bonds on the adjacent carbon.
Rotating the atoms on one carbon by 60° converts an eclipsed conformation into a staggered conformation, and vice versa.
Conformations are the same arrangements of atoms that cannot be interconverted by rotation about single bonds.
In the eclipsed conformation, the C-H bonds on one carbon bisect the H-C-H bond angle on the adjacent carbon.
Physical Chemistry
GeneralIf the theoretical yield of a reaction is 26.4 g and the actual yield is 18.7 g, what is the percent yield?
Physical Chemistry
GeneralHow much heat is produced by the combustion of 361 g of propene (C3H6)?
C3H6 (g) + 20₂(g) → 3CO2(g) + 3H₂O(1l) ΔH = -2058 kJ/mol
Select the correct answer below:
3.53 x 104 kJ
240 kJ
7.43 x 105 kJ
1.77 x 104 kJ
Physical Chemistry
GeneralA gas sample has a unknown pressure with a temperature of 57 °C. The same gas has a pressure of 2.47 atm when the temperature is -19 °C, with no change in the volume or amount
of gas.
Part A
What was the initial pressure, in atmospheres, of the gas?
Physical Chemistry
GeneralA solution is prepared by dissolving 5.50 grams of MgCl₂ in enough water to give 375 mL of
solution. Calculate (a) the molarity and (b) the normality of the solution. Show your work
and report your answers to 3 significant figures. (6 pts)
Physical Chemistry
General2. Iron can react with chlorine gas to give two different compounds, FeCl2 and FeCl3. If 0.558 g of
metallic iron reacts with chlorine gas to yield 1.621 g of an iron compound, which compound is
produced? Show work to prove.
Physical Chemistry
GeneralWhich of the following techniques could be applied to develop a personal narrative?
Use the pronouns I, me, my, we, us, and our when telling the story.
Include humor and exaggeration.
Carry out research on the topic to know the real facts of the event.
Physical Chemistry
GeneralA chemistry student is given 100. mL of a clear aqueous solution at 28.° C. He is told an unknown amount of a certain compound X is dissolved in the solution.
The student allows the solution to cool to 28.° C. The solution remains clear. He then evaporates all of the water under vacuum. A precipitate remains. The
student washes, dries and weighs the precipitate. It weighs 0.024 kg.
Physical Chemistry
GeneralYour final product crystallizes as a trihydrate compound. This means that:
Three water molecules are bonded to the iron.
Three water molecules are hydrolyzed during the reaction.
O Three water molecules are in the crystalline lattice.
Three water molecules are synthesized during the reaction.
Physical Chemistry
GeneralWhich of the following processes can be used for preparation of H2 gas?
Dissolving LiH in water
Reaction of Al with NaOH solution
Reaction of Zn with dilute H₂SO4
Electrolysis of H₂O in the presence of KOH
Physical Chemistry
GeneralWhich of the following is true about the concluding line "A warm, safe place to spend a
chilling night in the mountains is ready for you"?
The concluding sentence summarizes the results of the process.
The concluding sentence restates the controlling idea word by word.
The concluding sentence repeats the topic sentence word by word.
Physical Chemistry
GeneralFor the following reaction, 0.610 grams of hydrogen gas are allowed to react with 12.6 grams of ethylene (C₂H4).
hydrogen (g) + ethylene (C₂H4) (g)-ethane (C₂H6) (g)
What is the maximum amount of ethane (C₂H6) that can be formed?
What is the FORMULA for the limiting reagent?
What amount of the excess reagent remains after the reaction is complete?
grams
grams
Physical Chemistry
GeneralMISSED THIS? Watch KCV 8.2. IWE 8.2; Read
Section 8.4. You can click on the Review link to
access the section in your eText.
For the reaction shown, calculate how many grams
of oxygen form when each quantity of reactant
completely reacts.
2 HgO (s) → 2 Hg (1) + O₂ (g)
1.53 kg HgO
m =
VE
1.41
Submit P
▾ Part D
X Incorrect
3.64 mg HgO
Physical Chemistry
GeneralSelect the single best answer.
Classify the following reaction as oxidation, reduction, or neither.
CH3CHO → CH3CH₂OH
O
O
O
Oxidation
Reduction
Neither
Physical Chemistry
GeneralFor the reaction shown, find the limiting reactant for
each of the following initial quantities of
reactants.
2 Li (s) + Cl₂ (g) → 2 LiCl (s)
Part C
2.85 x 10³ g Li; 6.79 x 10³ g Cl₂
Express your answer as a chemical formula.
Physical Chemistry
GeneralConsider the reaction between NiS₂ and 0₂:
2 NiS2 (s) + 5 O2 (g) → 2 NiO (s) + 4 SO₂ (g)
When 11.2 g of NiS2 are allowed to react with 5.43 g
of O₂.4.52 g of NiO are obtained.
▼
m=
Submit
Part C
Request Answer
Determine the percent yield for the reaction.
Physical Chemistry
GeneralMISSED THIS? Watch KCV 8.5, IWE 8.5; Read
Section 8.6. You can click on the Review link to
access the section in your eText.
Consider the reaction between NiS₂ and 0₂:
2 NiS₂ (s) + 5 O₂ (g) → 2 NiO (s) + 4 SO₂ (g)
When 11.2 g of NiS2 are allowed to react with 5.43 g
of O₂.4.52 g of NiO are obtained.
Determine the limiting reactant for the reaction.
Express your answer as a chemical formula.
Submit
AΣ
A chemical reaction does not occur for this question.
▾ Part B
EMAND ?
Request Answer
Determine the theoretical yield of NiO for the reaction.
Revie
Physical Chemistry
GeneralA biochemist carefully measures the molarity of glycerol in 49. mL of photobacterium cell growth medium to be 18. µM.
Unfortunately, a careless graduate student forgets to cover the container of growth medium and a substantial amount of the solvent evaporates. The volume of
the cell growth medium falls to 17. mL. Calculate the new molarity of glycerol in the photobacterium cell growth medium.
Round each of your answers to 2 significant digits.
Physical Chemistry
GeneralBe sure to answer all parts.
The following IUPAC name is incorrect. Explain why it is incorrect and give the correct IUPAC name.
2-methyl-2-isopropylheptane
O
O
The compound name contains incorrectly
alphabetized substituents.
The compound name is spelled incorrectly.
Which of the following is the correct IUPAC name?
The compound has incorrectly
labeled substituents.
The longest chain was not chosen.
2,3,3-methyloctane O 1,1,2,2-tetramethylheptane
2,3,3-trimethyloctane
O 2-isopropyl-2-methylheptane
Physical Chemistry
GeneralYou are writing a narrative, and in between interrupting the plot to tell something that
happened before. What exactly is that you are adding to your narrative?
Flashback
Suspense
Foreshadow
Physical Chemistry
GeneralWhich of the following are anti conformers?
H
CH₂
H.
H
H
H
H
à 0 0
CH₂
H
H
H₂C
CH₂
CH3
CH₂
III
I
11
Multiple Choice
II and IV
II and III
I and IV
I and II
H
H₂C
H
H
IV
CH₂
H
ANDA
Physical Chemistry
GeneralIf 4.100 moles of water react completely, according to the following equation, what is the total change in enthalpy?
12
6CO₂ + 6H₂O C6H₁2O6 +60₂
AHrxn = 2,803 kJ
• Report your answer using four significant figures.
L
Physical Chemistry
GeneralWhat is the frequency of radiation (in MHz) with a
wavelength of 8850 nm?
Given speed of light = 3.00 x 108 m/s and c = Av
3.4 * 107 MHz
34 * 1019 MHz
O 30x 10¹ MHz
O 3.0×10¹5 MHz
3.4 x 10 MHz
0.030 MHz
Physical Chemistry
GeneralArrange the following electromagnetic regions in order of increasing wavelength:
microwave, green, red, yellow
Physical Chemistry
GeneralAn excess of sodium carbonate, Na₂CO3, in solution is added to a solution containing 15.03 g CaCl₂. After performing the
experiment, 13.33 g of calcium carbonate, CaCO3, is produced. Calculate the percent yield of this reaction.
Physical Chemistry
GeneralChoose the sentence that is capitalized correctly.
O
O
Samuel Adams (1722-1803) was an American Statesman, Politician, Writer, and political
Philosopher.
Samuel Adams (1722-1803) was an American statesman, politician, writer, and political
philosopher.
Samuel Adams (1722-1803) was an american statesman, politician, writer, and political
philosopher.
Physical Chemistry
GeneralIdentify the new word or phrase in the following passage.
Want to drop some weight? Avoid traffic jams? Identify a song on the radio? There's an
app for that.
O Drop
O Traffic jams
O App
Physical Chemistry
GeneralWhen 15.6 g of aluminum (26.98 g/mol) reacts with 14.3 g of oxygen gas (32.00 g/mol), what is the maximum mass (in grams) of
aluminum oxide (101.96 g/mol) that can be produced?
4 Al(s) + 3 O2(g) → 2 Al2O3(s)
Physical Chemistry
GeneralIf 8.7 moles of Al and 2.7 moles of Fe203 are allowed to react completely, how many moles of the excess reactant will remain? (Please give your
answer with one decimal place even if one of the initial values does not show any decimal places.)
2AI + Fe2O3Al2O3 + 2Fe
Physical Chemistry
GeneralArrange the following in order of increasing energy: infrared, X-rays, microwave,
visible