General Questions and Answers
Physical Chemistry
Generalarning Goal:
use the equilibrium constant and Le Châtelier's
nciple to determine how a reaction will respond
external factors.
reaction is at equilibrium when the concentrations
the reactants and products no longer change
er time. This does not mean the reaction is over;
ther, two competing reactions continue to occur
multaneously at equal rates. The two competing
eactions are the forward reaction (reactants →→
roducts) and the reverse reaction (products →
eactants).
f a reaction at equilibrium is subjected to a stress,
the concentrations of reactants and products adjust
to reestablish equilibrium. This is called Le
Châtelier's principle. A stress might be a change in
the concentration of reactants or products, a
change in the volume of the reaction container, a
change in temperature, or the addition of a catalyst.
The following reaction is at equilibrium in a 2.0-L vessel:
2SO2(g) + O2(g) = 2SO3(g),
How do the following actions affect the equilibrium of the reaction?
Drag the appropriate items to their respective bins.
►View Available Hint(s)
Shift to reactants
increase volume
decrease volume
Shift to products
add sulfur dioxide gas
remove oxygen gas
No shift
K=1.4 x 10¹
Reset Help
Revie
add catalyst
Physical Chemistry
GeneralThe specific heat capacity of solid tungsten is 0.133 J/g °C.
(a) Determine the amount of heat energy that is associated with heating a 13.3-g sample of solid tungsten from 24.2
°C to 35.9 °C.
J
(b) Calculate the final temperature reached when 124 J of heat is added to a 25.0-g sample of solid tungsten initially
at 24.2 °C.
°C
Physical Chemistry
GeneralTwo new elements have been discovered: Adamantium (Ad) and Serpentine (Ss)! Adamantium has been proven to have three valence
electrons. Serpentine has been proven to have six valence electrons. Based on this information, identify the subscripts for the expected
chemical formula for the combination of these two elements. Use a "1" when needed.
Ad
Blank 1:
Blank 2:
Ss
Physical Chemistry
GeneralConsider the 1.12 litre mixture of O, and O, at 0°C and 1 atm pressure
which is allowed to react with excess of aqueous solution of KI. The reac-
tion occurs as follows (unbalanced)
KI + H₂O + O₂ → KOH + 1₂ + O₂
The liberated I, required 80 ml of sodium thiosulphate for titration. The
2
mass of H₂O₂ required to produce that much amount of O₂ which is present
in given initial gaseous mixture. (Report the answer to the nearest integer)
Physical Chemistry
GeneralLearning Goal:
To use the equilibrium constant and Le Châtelier's
principle to determine how a reaction will respond
to external factors.
A reaction is at equilibrium when the concentrations
of the reactants and products no longer change
over time. This does not mean the reaction is over;
rather, two competing reactions continue to occur
simultaneously at equal rates. The two competing
reactions are the forward reaction (reactants →
products) and the reverse reaction (products →→
reactants).
If a reaction at equilibrium is subjected to a stress,
the concentrations of reactants and products adjust
to reestablish equilibrium. This is called Le
Châtelier's principle. A stress might be a change in
the concentration of reactants or products, a
change in the volume of the reaction container, a
change in temperature, or the addition of a catalyst.
Given the concentrations, calculate the equilibrium constant for this reaction:
PC13 (g) +Cl₂ (g) = PCL5 (g)
At equilibrium, the molar concentrations for reactants and products are found to be [PC13] = 0.20 M, [Cl₂] = 0.25 M,
and [PC15] 1.20 M. What is the equilibrium constant (Kc) for this reaction?
Express your answer using two significant figures.
► View Available Hint(s)
K = 24
Submit
=
Part B
✓ Correct
Previous Answers
[PC15]
[PC13][Cl₂]
The concentration of PC13 (g) is increased to 1.2 M, disrupting equilibrium. Calculate the new ratio of products to
reactants with this higher concentration of phosphorus trichloride. Assume that the reaction has not yet regained
equilibrium.
Express your answer using two significant figures.
► View Available Hint(s)
=
Review | Constants | Periodic Table
VAEO
?
Physical Chemistry
GeneralWhat is true about covalent compounds?
Select the correct answer below:
They have the same properties as ionic compounds.
O They are formed when one atom transfers an electron to another.
O They are formed when atoms share electrons between each other.
O They only form between metals.
Physical Chemistry
GeneralIf a solid line represents a covalent bond and a dotted line represents intermolecular attraction, which of the choices shows a
hydrogen bond?
[ HẠN…H-O-H
H₂OH-CH3
H₂C......H-F
H-H
Physical Chemistry
GeneralA sample of xenon gas occupies a volume of 8.32 L at 475 K. If the pressure remains constant, at what temperature will this
same xenon gas sample have a volume of 5.14 L?
T =
K
Physical Chemistry
GeneralConcluding something with a lesson you have learned because of the experience you
wrote about or the story you just described is an example of
concluding with a mystery
O concluding with a summary
concluding with a personal comment
Physical Chemistry
GeneralQuestion 10 (2 points)
Suppose that three newly discovered elements, tellpunsnine (Tp), arcanine (Wf), and feline (Mw) have 5, 6, and 7 valence electrons, respectively_
Based on this information, identify the number of electron domains and the bond angle of the center atom in the structure for WfMw2.
Electron domains:
Bond angle:
Blank 1:
Blank 2:
Physical Chemistry
GeneralQuestion 1 (1 point)
The newly discovered element serpentine (Ss) can be combined with the newly discovered element draconine (Dr) to form the molecular
compound SsDr4. A student suggests that this compound should be named monoserpentine tridraconide. Select ALL the following statements
that apply to this suggestion.
☐a
Ob
C
Od
e
f
Og
h
A prefix was used for serpentine when it should not have been.
A prefix was used for draconine when it should not have been.
The wrong prefix was used for serpentine.
The correct prefix was used for serpentine.
The wrong prefix was used for draconine.
The correct prefix was used for draconine.
A prefix was not used for serpentine when it should have been.
A prefix was not used for draconine when it should have been.
Physical Chemistry
GeneralExpressing amounts of energy in different energy units is necessary to solve many chemistry
problems. For practice, complete the following table.
The Joule (J) is the SI unit of energy.
1 calorie (cal) = 4.184 J
J
649
cal
178
kJ
0.866
Physical Chemistry
GeneralA Honda Civic Hybrid weighs about 3000 lb.
Y
Submit
Previous Answers
Answer Requested
Part B
Calculate the mass of the car in kilograms. (Note: 1 kg on Earth's surface has a weight of 10 N).
Express your answer to two significant figures and include the appropriate units.
Physical Chemistry
Generalwhen
A business jet of mass 22000 kg takes off
the thrust for each of two engines is 24000 N
Part A
Find its acceleration.
Physical Chemistry
GeneralSuppose you have been handed 3 powdered solids, A, B, and C. Design of series of tests that you could use to determine the difference
between each powder if you are told that one of them is ionic, one of them is metallic, and one of them is molecular. Justify your choice in
procedures.
Physical Chemistry
GeneralA sample of nitrogen gas was collected via water displacement. Since the nitrogen was collected via water displacement, the
sample is saturated with water vapor. If the total pressure of the mixture at 21 °C is 1.65 atm, what is the partial pressure of
nitrogen? The vapor pressure of water at 21 °C is 18.7 mm Hg.
Physical Chemistry
GeneralPolyatomic ions are groups of tightly bonded atoms that behave like a monoatomic ion when bonding.
How do the -ate versions of the ions differ form the -ite versions?
the -ate versions of the anions have 1 more oxygen atom than the -ite versions
the-ate and -ite versions have the same number of oxygen atoms
the -ite versions of the anions have 1 more oxygen atom than the -ate versions
some of the -ate version of the ion have two more oxygen atoms than the -ite versions of the anions
Physical Chemistry
GeneralThe extraction of aluminum metal from the aluminum hydroxide found in bauxite by the Hall-Héroult process is one of the most remarkable success stories of
19th century chemistry, turning aluminum from a rare and precious metal into the cheap commodity it is today. In the first step, aluminum hydroxide reacts to
form alumina (Al₂O,) and water:
2Al(OH), (s) Al₂O, (s) + 3H₂O(g)
In the second step, alumina (Al₂O3) and carbon react to form aluminum and carbon dioxide:
2Al₂O3(s) + 3C(s) 4Al(s) 3 CO₂ (g)
Suppose the yield of the first step is 89.% and the yield of the second step is 80.%. Calculate the mass of aluminum hydroxide required to make 6.0 kg of
aluminum.
Be sure your answer has a unit symbol, if needed, and is rounded to 2 significant digits.
Physical Chemistry
GeneralA 25.0-mL sample of potassium chloride solution was found to have a mass of 25.225 g.
After the solution was evaporated to dryness, the mass of the KCl residue was 1.396 g.
Calculate the (a) mass/mass percent concentration, and (b) molarity of the solution.
Physical Chemistry
GeneralIn the chemical formula for binary compounds sometimes there are roman numerals. What does the roman numeral represent?
the roman numeral indicates the number of anions in the formula
the roman numeral indicates the number of cations in the formula
the roman numeral represents the charge on the anion when the anion has more than one possible charge
The roman numeral represents the charge on the cation when the cation has more than one possible charge
Physical Chemistry
GeneralWhat is the role of a conclusion in a story?
O It will have to provide a happy ending.
O It should provide nothing other than a moral.
It has to tie up all the loose ends created in the story.
Physical Chemistry
GeneralThere are two steps in the usual industrial preparation of acrylic acid, the immediate precursor of several useful plastics. In the first step, calcium carbide
(CaC₂) and water react to form acetylene (C₂H₂) and calcium hydroxide:
CaC₂ (s) + 2H₂O(g)
C₂H₂(g) + Ca(OH)₂ (s)
In the second step, acetylene (C₂H₂), carbon dioxide and water react to form acrylic acid (CH₂CHCO₂H):
6C₂H₂(g) + 3C0₂(g) + 4H₂O(g) → 5 CH₂CHCO₂H (g)
1
Suppose the yield of the first step is 63.% and the yield of the second step is 80.%. Calculate the mass of calcium carbide required to make 4.0 kg of acrylic
acid.
Be sure your answer has unit symbol, if needed, and is rounded to 2 significant digits.
Physical Chemistry
GeneralBalance the following redox reaction if it occurs in basic solution. What are the coefficients in
front of Ni and H+ in the balanced reaction?
Show your work to get credit. Your work should include half reactions, balancing them
individually, and putting them together to get a balanced equation.
Ni+2(aq) + NH4+ (aq) → Ni(s) + NO3(aq)
Physical Chemistry
General3. 16.2 grams of ZnO are reacted with 45.0 mL of 6.0 M HCI solution.
a) Write a balanced equation for the reaction.
b) Which reactant is the limiting reagent? Must calculate.
c) Calculate the theoretical yield (grams) of salt produced.
d) If 0.105 moles of salt are produced, what is the % yield?
Physical Chemistry
General22. Consider the neutralization reaction H₂SO4 + 2 KOH
450 mL of a KOH solution with unknown concentration, what is the concentration of KOH?
2 H₂O + K2SO4. If there is 745 mL of 0.45 M H₂SO4 reacting with
Physical Chemistry
General1
Cu + 4 HNO3
Cu(NO3)2 + 2 H₂O + 2 NO2
a) How many grams of Cu(NO3)2 can be made from 25 grams of copper?
1
b) How many grams of NO2 can be made from 1.4 moles of copper?
c) How many moles of H₂O can be made from 8.0 mL of 16 M HNO3?
2. How many grams of HCI are present in 45.0 mL of 12.0 M HCI solution?
Physical Chemistry
GeneralA 35.6 g sample of ethanol (C2H5OH) is burned in a bomb calorimeter that has a
heat capacity of 23.3 kJ/°C. If the temperature rose from 35.0 °C to 76.0 °C, what
is the value of AErxn (in kJ/mol ethanol)?
C₂H5OH (1) + 3 O₂ (g) → 2 CO₂ (g) + 3 H₂O
Physical Chemistry
GeneralWhen naming ionic compounds, you will need to use your periodic table of ions. When writing the formula,
you write the ions for each and criss-cross the charges if they don't cancel out. Reduce them, if needed!
For example:
barium acetate
APCIO,
Write the names or formulas for the following compounds.
Formula
Name
CaCO,
Ni(CIO₂)2
KHCO,
Caso
AI(H₂PO₂),
NaCl
FROH
For example:
(NH4)₂CO3
Formula
Ba(C,H,O₂)
aluminum chlorate=
Na₂SO4
(NH4)₂CO3
Ba(C₂H₂O₂)2
Mg3(PO4)2
Carbonate
Nickel(1)
***Tip: Acetate can be written as C,H,O, or CH₂COO
AI(CIO,),
-1
Name
Cesium orthosilicate
Rubidium acetate
Potassium Hydride Carbonate Beryllium bromate
Cadmium Sulfite
Sodium borate
SbPO
Li-S
Na₂O₂
SnSO4
(NH) BO,
Be(CIO₂)2
NH,OH
Bismuth (III) sulfate
Write the correct name for the following compounds and then tell the number of atoms present in each of the
following formulas.
Name
Barium hydroxide
Potassium oxide
Silver sulfite
Lead (II) acetate
Barium phosphide.
Calcium oxalate.
Potassium sulfite
Magnesium arsenate
Antimony (V) nitrite
N: 2 H: 8 C: 1 0:3 Total # of atoms = 14
Formula
# of atoms
Physical Chemistry
GeneralWhich two atoms only need a duet (2) of valence electrons to become stable? Complete the blanks with proper element symbols.
The atoms that need only 2 valence electrons to have a complete valence shell are type your answer...
and
type your answer..
Physical Chemistry
GeneralWhat bond angle(s) is (are) present in the ficticious molecule AX4 if atom A is in group 4A (14) and atom X is in group 7A (17)? Only write a number or numbers separated by a comma. You do not need to include the
degree symbol.
Physical Chemistry
General3. Complete each ionization reaction and then identify the conjugate acid/base pair from that ionization reaction. Note that each ionization reaction contains two
conjugate acid/base pairs; these drop-downs are looking for the conjugate acid/base pair that does not involve water.
a.
b.
C.
d.
Reactants
HBr (aq) + H₂O (1) —
HCIO4 (aq) + H₂O (1) —
NH3 (aq) + H₂O (1) -
H₂CO3(aq) + H₂0 (1) —
Choose...
Choose...
Choose..
Choose...
Choose...
Choose...
Choose...
Choose...
Products
Conjugate Acid
Choose...
Choose...
Choose..
Choose...
Choose
Choose...
Choose..
Choose...
Table view
Conjugate Base
Choose...
Choose... -
Choose...
Choose...
Choose...
Choose...
List view
Choose..
Choose...
Physical Chemistry
GeneralDraw the Lewis structure of CIBr, showing all
lone pairs.
Select Draw Rings More
10
3 Ć
D
90°
109.5⁰
120"
180"
Br
What are the approximate bond angles in CIBr,?
Erase
Q2Q
Identify the molecular geometry of CIBr,..
square planar
bent
O tetrahedral
octahedral
O trigonal pyramidal
see-saw
O trigonal bipyramidal
O square pyramidal
trigonal planar
O linear
O T-shaped
A CIBr, molecule is
O polar.
nonpolar.
Physical Chemistry
GeneralClassify each reaction type:
1) MN + QP → QN + MP
2) CxHyOz + Oz - H2O + CO2
3) JRR+J
4) B+D
5) K+ EP
1
2
3
4
5
->>
BD
-
E + KP
[Choose ]
[Choose]
synthesis
single replacement
double replacement
decomposition
triple replacement
combustion
[Choose ]
Physical Chemistry
GeneralThere are two steps in the extraction of copper metal from chalcocite, a copper ore. In the first step, copper(I) sulfide and oxygen react to form copper(1) oxide
and sulfur dioxide:
2Cu₂S (s) + 30₂ (8)
2 Cu₂O(s)
+ 2 SO₂ (g)
In the second step, copper(I) oxide and carbon react to form copper and carbon monoxide:
Cu₂O(s)
+ C(s)
2Cu(s) + CO (g)
-
Suppose the yield of the first step is 89.% and the yield of the second step is 90.%. Calculate the mass of oxygen required to make 9.0 kg of copper.
Be sure your answer has a unit symbol, if needed, and is rounded to 2 significant digits.
Physical Chemistry
GeneralAs discussed in the live session, which type of chemical reaction is represented below?
2Mgl2 + Mn(SO3)2 --> 2MgSO3 + Mnl4
O double replacement
O single replacement
O synthesis
O decomposition
Physical Chemistry
GeneralTwo ionic compounds (or an acid and a base) react to produce two new compounds. This best describes a
reaction.
MX+NP-
O single replacement
O double replacement
synthesis
Odecomposition
O combustion
Physical Chemistry
GeneralThe mass of a starch packing peanut is 0.186 g. How much water (in g) would be needed to added to prepare a 3.04 % (w/w%) starch solution?
Physical Chemistry
GeneralA) N₂ +
B)______ KCIO3
NaCl +
C)
D)
E)
G)
H)
DA
OB
O C
D
DE
C8H18 +
FeCl3 +
F)______P+_____0₂ → P₂O5
H₂O →
OF
DG
1
Na +
OH
H₂
H₂SO4 +
-
1
KCI +
NH3
02
F₂-
_O₂ →_______CO₂ +
NaOH →
NaF +
From the unbalanced reactions above, which ones are a type or rep
double replacement)? Select the four correct answer.
NaOH +
Ba(NO3)2 -
Cl₂
H₂O
Fe(OH)3 + NaCl
H₂
HNO3 +
BaSO4
Physical Chemistry
GeneralA solution is prepared by mixing 69.0 mL of a 0.196 M NaCl solution with 23.0 mL of a 0.294 M CaCl, solution. Determine the
volume in milliliters of a 0.1111 M AgNO, solution needed to precipitate all of the Cl" as AgCl.
volume AgNO3 =
mL
Physical Chemistry
GeneralWrite the equilibrium-constant expression for the reaction
A(s) + 3 B(l) -> 2 C(aq)+D(aq)
in terms of [A], [B]. [C], and [D], as needed.
Note that Ke, which is sometimes symbolized as Keq, denotes that the equilibrium constant is expressed using molar concentrations. For this question, Ke means the same thing as Keq.
Kc =
Physical Chemistry
GeneralThe human body can get energy by metabolizing proteins, carbohydrates or fatty acids, depending on the circumstances. Roughly speaking, the energy it gets
comes mostly from allowing all the carbon atoms in the food molecules to become oxidized to carbon dioxide (CO₂) by reaction with oxygen from the
atmosphere. Hence the energy content of food is roughly proportional to the carbon content.
Let's consider lysine (C6H₁4N2₂O₂), one of the amino acids from which proteins are made, and oleic acid (C₁8H3402), a fatty acid from which fats are made.
Using the idea above about energy content, calculate the ratio of the energy the body gets metabolizing each gram of lysine to the energy the body gets
metabolizing each gram of oleic acid.
Round your answer to 2 significant digits.
Physical Chemistry
GeneralDraw the Lewis structure of CH₂NH and then choose the appropriate pair of
hybridization states for the two central atoms. Your answer choice is independent
of the orientation of your drawn structure.
-
A) sp / sp²
B) sp² / sp²
C) sp² / sp³
D) sp³ / sp³
E) sp³ / sp
Physical Chemistry
GeneralFor each of the following, declare whether the paired species do or do not constitute a
conjugate acid-base pair.
HCIO4 and HCIO3
pair
NH₂ and NH3
do not
H₂CO3 and HCO3 do
pair
H3PO4 and H3PO3
pair
do
NO₂ and HNO₂
NH3 and NH4
H3O* and H₂O do
do
do
do not
H₂O and OH do
>
V
constitute a conjugate acid-base
constitute a conjugate acid-base pair
constitute a conjugate acid-base
constitute a conjugate acid-base
constitute a conjugate acid-base pair
constitute a conjugate acid-base pair
constitute a conjugate acid-base pair
constitute a conjugate acid-base pair
Physical Chemistry
GeneralFor the following reactions, indicate whether the following are examples of synthesis,
decomposition, combustion, single displacement, or double displacement reactions.
Na3PO4 +3KOH3NaOH
+ K3PO4
1)
Physical Chemistry
GeneralThe equilibrium system between nitrogen gas, oxygen gas, and nitrogen dioxide gas is given.
N₂(g) +20₂ (g) = 2 NO₂(g)
Write the balanced chemical equation for the reverse reaction. Include physical states for all species.
chemical equation:
Physical Chemistry
General. Potassium ferricyanide reacts with sulfuric acid and water to produce potassium
sulfate, Iron(III) sulfate, ammonium sulfate and carbon monoxide by the following
balanced chemical reaction.
a. K.Fe(CN) + 6 H₂SO4 + 6 H₂O → 2 K₂SO4 + FeSO, +3 (NH4)2SO4 +6 CO
b. If 20 grams of K.Fe(CN), is reacted with 24.5 grams of H₂SO4, and 5
grams of H₂O which is the limiting reagent?
c.
Limiting reagent
d. How many grams of CO will be produced? Grams
e. If 5.2 grams of CO are produced, what is the % yield for the reaction?
f.
% yield
Physical Chemistry
GeneralReynolds, Glenn Harlan. "Glenn Reynolds: After Yale, Mizzou, raise the voting age - to
Web. 27 June 2017.
25." USA Today. Gannett Satellite Information Network,
What is missing from this MLA citation?
O The author's first name
The author's last name
The date it was published
Physical Chemistry
GeneralWhat mass of sodium chloride is produced when chlorine gas reacts with 0.29
grams of sodium iodide? The unbalanced equation is given below:
Nal (s) + Ch (g) → NaCl (s) + I2 (g)
Physical Chemistry
GeneralHow many grams of calcium carbonate are formed if 25.0 mL of 0.560M calcium
chloride and 32.4 mL of 0.489 M sodium carbonate are mixed together. The
balanced reaction is given below.
CaCl₂ (aq) + Na₂CO3(aq)
a. What is the limiting reagent?
b. How many grams of CaCO3 will be produced?
-
CaCO3(s) + 2 NaCl(aq)
Physical Chemistry
GeneralIf a solution containing 24.25 g of lead(II) acetate is allowed to react completely with a solution containing 7.410 g of sodium sulfate, how many grams of solid precipitate will be formed?
mass of solid precipitate:
How many grams of the reactant in excess will remain after the reaction?
mass of excess reactant: