Equilibrium Questions and Answers
Physical Chemistry
EquilibriumIdentify Sr(OH)2 (aq) as an acid or a base.
acid
base
Part D
Write a chemical equation showing how this is a base according to the Arrhenius definition.
Express your answer as a balanced chemical equation. Identify all of the phases in your answ
A chemical reaction does not occur for this question.
Physical Chemistry
EquilibriumConsider two solutions, the first being 60.0 mL of 1.00 M CuSO, and the second 60.0 mL of 2.00 M KOH. When the two solutions are mixed in a constant-pressure calorimeter, a precipitate forms and the temperature of the mixture rises from 23.5 to 29.7°C.
a. Write the chemical equation showing the precipitation reaction being described.
Clearly label the precipitate formed.
b. Write the complete and net-ionic equations for the reaction that occurs when the two solutions are mixed.
Physical Chemistry
EquilibriumA sealed container of methanol (CH3OH) contains both the liquid and gas in equilibrium:
CH3OH(l)<->CH3OH(g) ΔH = +37.61 kJ/mol
Indicate whether these changes would shift the equilibrium to the left or to the right.
Physical Chemistry
EquilibriumEquilibrium describes the balance that results from a forward and reverse reaction proceeding at equal rates. Since reaction ratesdepend on concentration, temperature, and pressure, any changes in these conditions may alter the forward and reverse rates unequally and disrupt the equilibrium.
Le Chatelier's principle states that after a change in conditions displaces a reaction from equilibrium
the reaction proceeds to a new equilibrium in the direction that offsets the change.
the reaction will undergo a temperature change in order to offset the disturbance.
the disturbance will always cause the forward reaction to be slower than the reverse reaction.
the change in conditions must be reversed in order to regain equilibrium.
Physical Chemistry
EquilibriumA 5 mL sample of vinegar (HC₂H3O2(aq)) requires a 37.28 mL of 0.127 M NaOH to reach the equivalent point. What is the molar concentration of HC₂H3O2? The equation for the reaction is
HC₂H3O2 + + NaOH -> NaC₂H3O2 + H₂O
(Answer to 3 decimal places)
Physical Chemistry
EquilibriumFor the reaction A (g) → 3 B (g), Kp = 73900 at 298 K. When AG -
-14.2 kJ/mol, what is the partial pressure of A when the partial
pressure of B is 2.00 atm for this reaction at 298 K.
Physical Chemistry
EquilibriumA 52.0-mL volume of 0.35 M CH3COOH (K₁ = 1.8 x 10-5) is titrated with 0.40 M NaOH. Calculate the pH after the addition of 23.0 mL of NaOH.
Express your answer numerically.
Physical Chemistry
EquilibriumA beaker with 185 mL of an acetic acid buffer with a pH of 5.000 is sitting on a benchtop. The
total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 7.10 mL
of a 0.480 M HCl solution to the beaker. How much will the pH change? The pKa of acetic
acid is 4.740.
Express your answer numerically to two decimal places. Use a minus ( - ) sign if the
pH has decreased.
Physical Chemistry
EquilibriumAn excess amount of Mg(OH)₂ is mixed with water to form a saturated solution. The resulting solution has a pH of 9.10.
Calculate the solubility, s, of Mg(OH)₂ (s) in grams per liter in the equilibrium solution. The Ksp of Mg(OH)₂ is 5.61 x 10-¹2.
S =
3.9
Incorrect
g/L
Physical Chemistry
EquilibriumWhen a chemical reaction is at equilibrium, the
forward and reverse reactions occur at the same
rate. The concentrations of the different compounds
in the reactions will remain constant. The
relationship between the concentrations of the
reactants and products is expressed as the
equilibrium constant, Ke.
Determine the Ke expression for the reaction above by identifying what belongs in the numerator and what belongs in the
denominator:
=1/4
Drag each item to the appropriate bin.
► View Available Hint(s)
Numerator
[COC1,]2
[0₂]²
[CCL]2 | |[C12]2 |
numerator
K=
denominator
Denominator
[Cl₂]
[CCL]
[COC1]
Not used
Reset Help
[0₂]
Physical Chemistry
EquilibriumClassify each of these solids as ionic, molecular, metallic, or covalent (also known as covalent-network solids or
macromolecular solids).
Na₂S
Ionic
C(diamond)
Na
Molecular
CC14
Answer Bank
Metallic
Covalent
Physical Chemistry
Equilibrium5. A 500.0 ml solution of a buffered solution has a pH = 7.4.
a) What is the [H3O+]?
b) If a few drops of dilute HCl were added what would happen to the pH?
c) If a few drops of dilute NaOH were added what would happen to the pH?
Physical Chemistry
EquilibriumAn excess amount of Mg(OH), is mixed with water to form a saturated solution. The resulting solution has a pH of 9.10.
Calculate the solubility, s, of Mg(OH)₂ (s) in grams per liter in the equilibrium solution. The Ksp of Mg(OH)₂ is 5.61 x 10-12.
Physical Chemistry
Equilibrium15. Provide the reactions that describe when H30* (acid) and OH (base) is added to the buffer solution.
Normal = BIU
Reaction of buffer with H₂O*(acid)
Reaction of buffer with OH (base)
X₂ X²→→→→→
III
=
fx &
Physical Chemistry
EquilibriumThe reaction between nitrogen and hydrogen to produce ammonia is described by the following equilibrium reaction.
3H₂ + N₂2 NH3
What substances are present in the reaction mixture when equilibrium has been obtained?
ON₂
] H₂
NH
NH₂
Physical Chemistry
EquilibriumAt 850 K, the equilibrium constant for the reaction
2 SO₂(g) + O₂(g) = 2 SO, (g)
is K. = 15. If the given concentrations of the three gases are mixed, predict in which direction the net reaction will proceed
toward equilibrium.
Physical Chemistry
EquilibriumIn a saturated solution of an ionic compound in
water, there is an equilibrium between the solid
compound and the dissolved ions. The equilibrium
expression for this type of reaction is called the
solubility product constant, Ksp, which can be
calculated from the concentrations, in moles per
liter, of each ion in solution.
For example, the solubility reaction and solubility
product of barium carbonate, BaCO3, are
BaCO3(s) = Ba²+ (aq) + CO3²- (aq)
Ksp = [Ba2+][CO3²-]
Similarly, the solubility reaction and solubility
product of calcium sulfate, CaSO4, are
CaSO4(s) Ca²+ (aq) + SO4²- (aq)
Ksp = [Ca²+][SO4²-]
=
Part A
The solubility of barium carbonate, BaCO3, is 0.0100 g/L. Its molar mass is 197.3 g/mol. What is the Ksp of barium
carbonate?
Express your answer numerically.
► View Available Hint(s)
Ksp =
Submit
Part B
VAE
μА
The solubility product constant of calcium sulfate, CaSO4, is 7.10 x 10-5. Its molar mass is 136.1 g/mol. How many
grams of calcium sulfate can dissolve in 40.5 L of pure water?
Express your answer to three significant figures and include the appropriate units.
▸ View Available Hint(s)
Value
Units
Review I Constants I Periodic Table
?
?
Physical Chemistry
EquilibriumThe synthesis of methanol from carbon monoxide
and hydrogen gas is described by the following
chemical equation:
CO(g) + 2H2(g): CH3OH(g)
The equilibrium constant for this reaction at 25 °C
is Kc = 2.3 x 104. In this tutorial, you will use the
equilibrium-constant expression to find the
1
concentration of methanol at equilibrium, given the
concentration of the reactants.
▼
Correct
The equilibrium constant is expressed as
Kc =
[CH3OH]
[CO][Hz]?
Part B
Review | Constants | Periodic Table
The equilibrium-constant expression is a mathematical equation that can be rearranged to solve for any of the variables in
it. Rearrange the equilibrium-constant expression to solve for [CH3OH].
► View Available Hint(s)
Physical Chemistry
EquilibriumThe equilibrium constant, Kc, for the following reaction is 4.1x10-³.
N₂O4 (9) 2NO2 (g)
If the equilibrium mixture contains 0.045 M NO2, what is the molar concentration of N₂O4?
Express your answer to two significant figures and include the appropriate units.
μA
?
[N₂04] = 4.94
moler
The unit you entered is not recognized. Review a list of acceptable units.
No credit lost. Try again.
Bewer
Physical Chemistry
EquilibriumChoose the equilibrium expression for each of the
following reactions:
Part C
CH4 (9) + Cl₂(g)
O Ko
OK. =
Ke
Submail
CH3CI(g) + HCl(g)
=
[C1₂][CH4]
[HCI][CH, CI]
[CHC1s][Cl₂]
[CH][CH, CI]
[HCI||CH,Cl|
[C1₂][CH]
Request Answer
Physical Chemistry
EquilibriumConsider the following chemical reaction:
Heat + 2 NOCI (g) 2 NO(g) + Cl2(g)
Which of the conditions listed below will result in the equilibrium shifting toward the reactant side, according to Le Châtelier's principle?
View Available Hint(s)
increasing the concentration of NOCI (g)
O increasing the concentration of C12(g)
O heating the reaction
O adding a catalyst
Physical Chemistry
EquilibriumAmmonia, NH3, is used in numerous industrial processes, including the production of pharmaceuticals such as sulfonamide
and antimalarials and vitamins such as the B vitamins. The equilibrium equation for the synthesis of ammonia (sometimes
known as the Haber process) is
N₂(g) + 3H₂(g) = 2NH3(g)
Part A
The Haber process is typically carried out at a temperature of approximately 500 °C. What would happen to the rate of the
forward reaction if the temperature' were lowered to 100 °C?
► View Available Hint(s)
The reaction rate would
increase
O decrease
O not change
Physical Chemistry
EquilibriumAn equilibrium reaction has a Ke of 1.4 x 109. Which of the following accurately describes the chemical equilibrium for this reaction?
► View Available Hint(s)
O The concentrations of the products are approximately the same as the concentrations of the reactants.
O The concentrations of the reactants are less than the concentrations of the products. The equilibrium is said to favor the reactants.
O The concentrations of the products are less than the concentrations of the reactants. The equilibrium is said to favor the reactants.
O The concentrations of the products are greater than the concentrations of the reactants. The equilibrium is said to favor the products.
Physical Chemistry
Equilibrium(7 pts.) Which of the following solutions will be the best buffer at a pH of 3.47? Please explain fully.
(Please see the equation sheet for useful information).
A) 0.10 M CH3NH2 and 0.10 M CH3NH3C1
B) 2.5 M CH3NH₂ and 2.5 M CH3NH3Cl
C) 2.0 M HF and 2.0 M NaF
D) 3.0 M CH3NH2 and 3.0 M HF
Physical Chemistry
EquilibriumEphedrine and its salt are used for a variety of disorders. Calculate the ratio of the acid form
of the drug (ephedrine HCI) to the base form (ephedrine) in the stomach at pH 6.00. The pKa
of Ephedrine is 9.6. (4 pts)
Physical Chemistry
EquilibriumCalculate the pH of a solution prepared by dissolving 1.45 g of sodium acetate, CH3COONa, in 57.0 mL of 0.20 Macetic acid, CH3COOH(aq). Assume the volume change upon dissolving the sodium acetate is negligible. K₂ of CH3COOH is 1.75 x 10-5.
Physical Chemistry
EquilibriumA chemist fills a reaction vessel with 9.81 atm methanol (CH3OH) gas, 2.78 atm oxygen (O₂) gas, 9.08 atm carbon dioxide (CO₂) gas, and 5.38 atm water
(H₂O) gas at a temperature of 25.0°C.
Under these conditions, calculate the reaction free energy AG for the following chemical reaction:
2CH₂OH(g) +30₂ (g) 2 CO₂(g) + 4H₂O(g)
Use the thermodynamic information in the ALEKS Data tab. Round your answer to the nearest kilojoule.
Physical Chemistry
EquilibriumA chemist dissolves 472. mg of pure barlum hydroxide in enough water to make up 190. mL of solution. Calculate the pH of the solution. (The temperature of
the solution is 25 °C.)
Round your answer to 3 significant decimal places.
Physical Chemistry
EquilibriumTask 1: Research (you should've done this in your checkpoint)
If you are going to use red cabbage to make your own pH indicator, you first need to understand
how a pH indicator works. Do some research into pH and how litmus paper can be used to
measure it. Then research red cabbage and its relation to measuring pH. You'll need to
document your sources as well. These are the sources that will eventually end up in your
"References" part of the lab report. I've created a checkpoint in Summit to help guide you
through this task.
Physical Chemistry
EquilibriumA chemist dissolves 490. mg of pure barium hydroxide in enough water to make up 160. mL of solution. Calculate the pH of the solution. (The temperature of the solution is 25 °C.)
Round your answer to 3 significant decimal places.
Physical Chemistry
EquilibriumThe preparation of an aqueous solution is described in the table below. For this solution, write the chemical formulas of the major species present at equilibrium. You can leave out water itself.
Write the chemical formulas of the species that will act as acids in the 'acids' row, the formulas of the species that will act as bases in the 'bases' row, and the formulas of the species that will act as neither acids nor bases in the 'other' row.
You will find it useful to keep in mind that NH3 is a weak base.
0.4 mol of HNO3 is added to
1.0 L of a 0.4M NH3
solution.
Physical Chemistry
EquilibriumPay attention to the reaction letter as they are referenced throughout this section.
Write equilibrium expressions for each following reaction
a. NaOH(aq) + HCl(aq) -> H₂O(l) + NaCl(aq)
b. K₂SO4 (aq) + Ca(NO3)2(aq) -> 2 KNO3 (aq) + CaSO4(s)
c. 4NO(g) + 3O2(g) -> 2N2O5 (g)
d. C3H8(l) + 5O₂(g) -> 3CO2(g) + 4H2O(l)
e. 2 H₂O(l) -> 2H₂(g) + O₂(g)
Physical Chemistry
EquilibriumWhich is an example of a heterogeneous equilibrium system?
Fe³+ (aq) + SCN- (aq) FeSCN²+ (aq)
NO₂(g) + NO(g) = N₂O3(g)
Cu²+ (aq) + 2OH(aq) = Cu(OH)2(s)
2H₂(g) + O₂(g) = 2H₂O(g)
Physical Chemistry
EquilibriumSuppose that 8.00 mol of both O2 and N2O gases are introduced into a 4.00 L closed flask. When the system comes to equilibrium, 3.00 mol of nitrogen monoxide (NO) gas has formed. The reaction is shown below.
Determine the equilibrium concentrations of all entities in the flask, NO, NO2 and 02. (6 marks)
*SHOW YOUR WORK!
2N₂O(g) + O₂(g) = 4NO(g)
DONE
Not done
Physical Chemistry
EquilibriumA chemistry student weighs out 0.168 g of acrylic acid (HCH₂CHCO₂) into a 250. mL volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.1600M NaOH solution.
Calculate the volume of NaOH solution the student will need to add to reach the equivalence point. Round your answer to 3 significant digits.
Physical Chemistry
EquilibriumA certain ionic compound X has a solubility in water of 0.648 g/mL at 20. °C. Calculate the greatest mass of X that could be dissolved in 450. mL of water at this temperature. You may assume the volume of the solution doesn't change as the X is dissolved.
Be sure your answer has the correct unit symbol and 3 significant digits.
Physical Chemistry
EquilibriumIn the following acid-base equilibria of weak acids in water, label the acid (A), the base (B), the conjugate acid (CA), and the conjugate base (CB).
HCIO2(aq) + H2O(l) = H2O+ (aq) + ClO2- (aq)
H2CO3(aq) + H2O(l) = H3O+ (aq) + HCO3-(aq)
H2O(l) +CH3NH3+(aq) = CH3NH2 (aq) +H3O+(aq)
CH3COOH(aq) + H2O(l) = CH3COO- (aq) + H3O+ (aq)
Physical Chemistry
EquilibriumA certain organic compound O has a solubility in acetone of 0.799 at 5. °C. Calculate the mass of O required to prepare 650. mL of a saturated solution of
O in acetone at this temperature.
Be sure your answer has the correct unit symbol and 3 significant digits.
Physical Chemistry
EquilibriumWhich of the following is a nonelectrolyte?
KI
C6H12O6 (glucose)
HF
KOH
Physical Chemistry
EquilibriumConsider the titration of 50.0 mL of 2.0 M HNO2 (K = 4.0x104, a weak acid) with 1.0 M KOH (a strong base). What is the pH at the equivalence point?
Physical Chemistry
EquilibriumIt is found that up to 0.0110 g of SrF2 dissolves in 100 mL of aqueous solution at a certain temperature. Determine the value of Ksp for SrF2.
Physical Chemistry
EquilibriumWrite a net ionic equation for the reaction that occurs when aqueous solutions of potassium hydroxide and hydroiodic acid are combined.
Physical Chemistry
EquilibriumCalculate the number of milliliters of 0.697 M Ba(OH)₂ required to precipitate all of the Cr³+
ions in 197 mL of 0.414 M Cr₂(SO4)3 solution as Cr(OH)3. The equation for the reaction is:
Cr₂(SO4)3(aq)+ 3Ba(OH)₂(aq) →→2Cr(OH)3(s) + 3BaSO4(aq)
mL Ba(OH)₂
Physical Chemistry
EquilibriumThe precipitate of M₂S3 is obtained on mixing equal volumes of solution S₁ having
[M³+] = 4 x 10-4 Mand S₂ having [S²] = 2 × 10-³ M. Calculate its solubility products.
-
A
B
C
4 x 10-17
108 × 10-17
54 x 10-17
D 8 x 10-17
Physical Chemistry
EquilibriumCalculate the solubility at 25 °C of BaCrO4 in pure water and in a 0.0030 M BaCl₂ solution. You'll find Kp data in the ALEKS Data tab.
Round both of your answers to 2 significant digits.
Physical Chemistry
EquilibriumWhen an instant hot pack is activated, aqueous sodium acetate crystallizes to form a solid and
heat is released. What are the signs of AHsys, ASsys, AGsys, Suniv?
AH sys
AS sys
positive
AG sys
negative
ASuniv impossible to determine
As temperature increases, the reaction becomes
spontaneous.
Physical Chemistry
EquilibriumCalculate the solubility at 25 °C of Zn(OH)₂ in pure water and in a 0.0030 M ZnSO4 solution. You'll find K, data in the ALEKS Data tab.
sp
Round both of your answers to 2 significant digits.
Physical Chemistry
EquilibriumOzone, O, is an important absorber of UV radiation in our atmosphere. Upon absorption of UV
radiation, O, dissociates into molecular oxygen, O₂, and a free oxygen atom. The free oxygen
atom can then join with another O, molecule to create more ozone, which can in turn absorb
more UV radiation. Alternatively, the free oxygen atom could join with O, to create more 0₂.
2 O3(g) →3 O2(g)
The reaction would have a
Why? --
--
AS.
Physical Chemistry
EquilibriumA solution is prepared at 25 °C that is initially 0.41 Min trimethylamine ((CH₂), N). a weak base with K-7.4 x 10, and 0.35 M in trimethylammonium
chloride ((CH₂), NHCI). Calculate the pH of the solution. Round your answer to 2 decimal places.
PH-0
Physical Chemistry
EquilibriumAn analytical chemist is titrating 91.0 mL of a 0.4700 M solution of cyanic acid (HCNO) with a 0.7300 M solution of NaOH. The pK, of cyanic acid is 3.46.
Calculate the pH of the acid solution after the chemist has added 62.0 mL of the NaOH solution to it.
Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of NaOH solution added.
Round your answer to 2 decimal places.
PH-0