Equilibrium Questions and Answers

In a study of the formation of NO2, an atmospheric pollutant, a chamber heated to 25.0°C was filled with NO2. After the vessel sat for a while, the partial pressures of NO2 and the reaction product N₂O4 were 0.515 atm and 1.56 atm, respectively. What is the value of Kp for the balanced reaction shown? 2NO2(g) N₂O4(g) 0.330 5.88 0.803 3.03 0.170

Gaseous hydrogen and iodine can be used to prepare HI in the following balanced chemical reaction. Calculate a value for the reaction quotient when [H₂] = [I₂] = 4.67 x10³M and [HI] = 4.07 x 10-2M. H₂(g) +I2(g) 2HI(g) 132 x 10-2 1.87 x 103 5.36 x 10-4 1.77 x 10-1 76.0

Which expression corresponds to the equilibrium constant Kc for the reaction written as 2NH3(g) + 2O2(g) N₂O(g) + 3H₂O₂(g)?

Suppose a 500. mL flask is filled with 0.20 mol of Br2, 1.7 mol of OCl2 and 0.60 mol of BrOCI. The following reaction becomes possible: Br₂(g) + OCl₂(g) → BrOCI(g) +BrCl(g) The equilibrium constant K for this reaction is 0.802 at the temperature of the flask. Calculate the equilibrium molarity of OCI₂. Round your answer to two decimal places.

Which of the following combinations will produce a 0.4MNaCl solutions? A) Mixing 500 mL of 0.4M NaOH with 500 mL of 0.4M HCl B) Mixing 300 mL of 1.2M NaOH with 600 mL of 0.6M HCl C) Mixing 500 mL of 0.4M NaCl with 500 mL of water D) Diluting 500 mL of 0.4MHCl with water to a final volume of 1.0 L E) Diluting 400 mL of 0.6M HCl with water to a final volume of 1.0 L

A solution is made by mixing 50.0 g of A (molar mass=68.0 g/mol) and 50.0 g of B (molar mass=35.0 g/mol). At 25°C the vapor pressures of pure A and B are 285 and 132 mmHg, respectively. Calculate the information requested below. Enter your calculated answer below and be sure to upload your work and calculations to receive full credit. (Note: Correct answers without supporting work earn 0 points) a) Mole fraction of A in the solution: b) Vapor pressure of solution at 25°C in mmHg: c) Mole fraction of A in vapor above the solution:

HCI is a strong electrolyte. A bottle of HCI contains the label 0.015 M HCl(aq). Which statement concerning this HCI solution is FALSE? The hydronium ion concentration in this solution is 0.015 M. The solution contains dissolved H30* and CI ions only; no HCI molecules are present. The solution has a higher concentration of hydronium ions than hydroxide ions. The pH of the solution is 1.5. The solution is acidic

A solution NaOH(aq) contains 7.3 g NaOH(s) per 100.0 mL of solution. Calculate the pH and the pOH of the solution at 25 °C.

At 2000 °C, the equilibrium constant (Kc) for the following reaction is 2.4 x 10³. What is the value of Kp for the same reaction at the indicated temperature? 2 NO (g) N₂ (g) + O₂ (g) 8.3 x 107 2.4 x 103 6.4 x 107 4.5 x 105

Calculate the [H*] for (a) black coffee with a pH of 4.28 (Enter your answer as follows: 1.0E-2 for 0.010) (b) black tea with a pH of 6.26 (Enter your answer as follows: 1.0E-2 for 0.010) (c) green tea with a pH of 7.19 (Enter your answer as follows: 1.0E-2 for 0.010)

For the reaction Ag2S(s) = 2 Ag+(aq) + s2-(aq), what happens to the equilibrium position if the amount of solid silver sulfide is doubled? A) shifts to the left B) shifts to the right C) does nothing D) doubles E) halves

What is the theoretical yield of Calcium Phosphate from 17.2 g of Calcium hydroxide? 2 H3PO4+ 3 Ca(OH)2 → 6 H₂O + Ca3(PO4)2

How will the changes listed below affect the position of the following equilibrium? You have 4 attempts. 2 NO₂(g) NO(g) + NO3(g) a. The concentration of NO is increased. The equilibrium will b. The concentration of NO₂ is increased. The equilibrium will c. The volume of the system is allowed to expand to 5 times its initial value. The equilibrium will d. The concentration of NO3 is decreased. The equilibrium will e. The pressure is increased by adding Ar(g) to the vessel at a constant volume The equilibrium will

Stainless steel is an alloy composed of between 11 and 30% chromium by mass. It may also contain other elements, such as nickel or manganese. The alloy is rust resistant. A stainless steel alloy is to be analyzed for its chromium content. A 6.80 g sample of the steel is used to produce 250.0 mL of a solution containing Cr₂O A 100-ml portion of this solution is added to BaCl(aq). When the pH of the solution is properly adjusted, 0.145 g BaCrO, (s) precipitates. What is the percent Cr, by mass, in the steel sample? Express your answer to three significant figures and include the appropriate units.

Calculate the molarity of an acetic acid solution if 29.3 mL of an HC2H3 O2 solution is titrated with 22.3 mL of a 0.339 M KOH solution: HC₂H3O2 (aq) + KOH(aq) → H₂O(l)+ KC₂H3O2 (aq)

The overall formation constant (Kf) is the product of the formation constant of the individual steps: Bn= K = K₁ x K2 x K3 xx Kn In calculating the concentration of [Cu(NH3)4]2+ from [Cu(H₂O)4]2+, the stepwise formation constants are as follows: K₁ = 1.90 x 104 K2= 3.90 x 10³ K3 = 1.00 x 10³ K4 = 1.50 x 10² Calculate the overall formation constant (K) for the formation of [Cu(NH3)4]2+ from [Cu(H₂O)4]²+.

A solution has [H3O+] = 6.4x10-5 M. Use the ion product constant of water to find the [OH-] of the solution. Express your answer to two significant figures. Kw = [H3O+][OH¯]

Indicate whether each of the following solutions is an acidic, basic, or neutral solution: Sort these solutions into the proper categories. [OH-] = 4.5 x 10-³M [OH-] = 5.0 x 10-⁹M [H3O+] = 1.4 x 10-5M [H3O+] = 6.0 x 10-10 M

A solution is prepared that is initially 0.13 M in benzoic acid (HC6H5CO₂) and 0.22 M in potassium benzoate (KC6H5CO₂). Complete the reaction table below, so that you could use it to calculate the pH of this solution. Use x to stand for the unknown change in [H3O+]. You can leave out the M symbol for molarity.

A certain molecular compound M has a solubility in hexane of 0.541 g/mL at 20. °C. Calculate the mass of M that's dissolved in 550. mL of a saturated solution mL of hexane at this temperature. Be sure your answer has the correct unit symbol and 3 significant digits.

Calculate the pH at 25 °C of a 0.84M solution of ethylammonium bromide (C₂H5NH3Br). Note that ethylamine (C₂H5NH₂) is a weak base with a pKb of 3.19. Round your answer to 1 decimal place.

A solution is prepared at 25 °C that is initially 0.47 M in diethylamine ((C₂H5)₂NH) a weak base with Kb = 1.3 × 10-3, and 0.37 M in diethylammonium bromide ((C₂H5)₂NH₂Br). Calculate the pH of the solution. Round your answer to 2 decimal places.

If barium hydroxide is found to be a strong electrolyte, how should it be written in a total ionic equation? Ba(OH)2 Ba2+ and OH- BaOH Ba 2+ and 2OH-

A solution is prepared at 25 °C that is initially 0.38 M in chlorous acid (HClO₂), a weak acid with Ka = 1.1 × 10-2, and 0.042 M in potassium chlorite (KCIO₂). Calculate the pH of the solution. Round your answer to 2 decimal places.

Predict the products of the reaction below. That is, complete the right-hand side of the chemical equation. Be sure your equation is balanced and contains state symbols after every reactant and product. HCIO4 (aq) + H₂O(l) →

Suppose a 500. mL flask is filled with 1.5 mol of N₂ and 0.60 mol of NO. This reaction becomes possible: N₂(g) + O₂(g) → 2NO(g) Complete the table below, so that it lists the initial molarity of each compound, the change in molarity of each compound due to the reaction, and the equilibrium molarity of each compound after the reaction has come to equilibrium. Use x to stand for the unknown change in the molarity of N₂. You can leave out the M symbol for molarity.

Write the formula of the conjugate acid for each of the following bases: NO3- Express your answer as a chemical formula.

Enter the formula of the conjugate base for the acid H₂PO4-. Express your answer as a chemical formula.

The equilibrium constant Kp is 2.4 x 103 for the following reaction. 2NO(g) ========= N₂ (g) + O₂ (g) Calculate Q for the following sets of conditions and determine which system in equilibrium? For those not in equilibrium, in which direction will the system shift? a. PNO = 0.012 atm, PN2 = 0.11 atm Po2 = 2.0 atm b. PNO = 0.0078 atm, PN2 = 0.36 atm Poz2 = 0.67 atm P = 0.0062 atm, PN2 = 0.51 atm Po2 = 0.18 atm

an acid or base was titrated into distilled water or a buffer solution. Why was there a large pH change when the first 1 mL of acid or base was titrated into the distilled water solution? A. pH is independent of the identity of the solution. B. Distilled water is an acid and base simultaneously C. Distilled water is not a buffer D. Distilled water is a buffer

What is the pH of 250 mL of a 1.10 M solution of hydrochloric acid? Report your answer to three decimal places.

14.00 mL of water is added to 8.00 mL of a 0.328 M solution of lithium hydroxide solution What is the pH of the resulting solution? Report your answer to three decimal places.

The protein histone has an isoelectric point of 10.8. Suppose you did a pH titration of a solution containing histone. At what pH will the protein aggregate?

Which of the equations below is the correct equilibrium-constant expression for the following reaction? SOCI₂ (g) SO₂ (g) + Cl₂ (g)

The following reaction has a Kp value of 0.345 at 900 K. Does the equilibrium mixture contain more reactants or more products? 2 SO₂ (g) + O₂ (g) 2 SO3 (g) reactants products unable to determine base on provided data

You are given a solution of a weak acid, HX, with a pK₂ of 4.00. You are provided with a sodium salt, NaX, of the acid's conjugate base. Your goal is to generate a buffer with a pH of 4.36. What value must log([X-]/[HX]) have to make this possible? Report your answer to two decimal places.

For the following reaction, N₂(g) + 3 H₂(g) 2 NH3(g) K₂ = 5.2 x 10³ the partial pressures are as follows: partial pressure (atm) N₂ 5.0 H₂ 10 NH3 5.0 Calculate Q and compare it to Kp. Will the system shift to the left or the right to achieve equilibrium, or is it at equilibrium? Q = 5.0x10-³ shift left Q = 5.2x10³ at equilibrium Q = 200 shift left Q = 5.0x10-³ shift right

The equilibrium constant for the following reaction is 92.8 at a certain temperature. 4 A(g) + B₂(g) 3 C(g) 0.100 mol of A and 0.330 mol of B are present at equilibrium in a 5.00-L flask. What is the molar concentration of C In the flask at equilibrium? A. 9.93x10-3 M B. 4.53 M C. 9.80x10-7 M D. 0.145 M E. 0.497 M

Calculate the volume of 2.79 M sulfuric acid that would be needed to neutralize 85.8 mL of a 2.57 M aqueous ammonia solution. The equation for the reaction is H2SO 4(aq) + 2 NH 3( aq) 2 NH 4+ ( aq) SO 4-²(aq)

Which statement is a correct application of Le Châteller's principle? a. Addition of a substance to the left side of an equilibrium shifts it to the right. b. Any stress to the right side of a chemical equilibrium results in a shift to the left to relieve the stress. c. Heat added or taken away from a chemical equilibrium in which one side is exothermic will not shift the reaction. d. Responses b and c are correct.

2KCIO3(s) --> 2KCl(s) + 302(g) A 3.00-g sample of KCIO3 is decomposed and the oxygen at 24.0°C and 545 mmHg is collected. What volume of oxygen gas will be collected assuming 100% yield? A. 1.01 x 10^2 mL B. 1.25 x 10^3 mL C. 8.32 x 10^2 mL D. 5.55 x 10^2 mL

A highly acidic drip-stream flows out of an abandoned coal mine and changes the pH of a nearby pond from pH 6.9 to pH 3.9; this makes the hydronium ion concentration of the pond... Hydronium ion concentration is 3 times lower. Hydronium ion concentration is 1000 times lower. Hydronium ion concentration is 100 times higher. Hydronium ion concentration is 1000 times higher. Hydronium ion concentration is 3 times higher. Hydronium ion concentration is 10 times lower.

Le Châtelier's principle states that if a change in pressure, temperature or concentrations of species is applied to a system in equilibrium, the equilibrium will shift so as to counteract and relieve the effect of the constraint. Which statement is a correct application of Le Châtelier's principle? a. Removing a substance from the right side will shift the reaction to the right side. b. Adding a substance to the right side will shift the reaction to the right side. c. Removing a substance from the right side will shift the reaction to the left side. d. Chilling a reaction mixture will cause the equilibrium to remain unchanged.

If a reaction has an equilibrium constant of Keq = 2.7x10^-5, what would be true...? a. The concentration of products must exceed the concentration of reactants at equilibrium. b. The activation energy must be extremely small. c. The concentration of reactants must exceed the concentration of products at equilibrium. d. The reaction must be exothermic. e. The concentration of reactants must equal the concentration of products at equilibrium. e. The forward reaction goes nearly to completion.

Given a 0.01 M solution of the following three weak acids: Acetic acid (CH3COOH) which has Ka = 1.8x10^-5, Nitrous acid (HNO₂) Ka = 4.6x10^-4and Formic acid (HCOOH), Ka =1.8x10^-4 Which solution has the strongest weak acid? a. All are equally strong. b. Acetic acid c. Formic acid d. Nitrous acid

Names and K, values for four weak acids are listed below. The Acid Dissociation equilibrium constant (Ka) describes the extent to which the acid dissociates in water: HA (aq) + H₂O (l) <=> H3O+ (aq) + A- (aq) If a 0.10 M solution is made of each acid, which solution would have the lowest pH? A. Acetic acid (CH3COOH), K₂ = 1.8 x 10-5 B. hydrofluoric acid (HF), K₂ = 6.6 x 10-4 C. carbonic acid (H₂CO3), K₂ = 4.3 x 10-7 D.hypochlorous acid (HOCI), K₂ = 2.9 x 108

Which statement is true for a neutral aqueous solution? a. it has a pH = 7 b. it has a hydroxide ion concentration of 1 x 10-7 M c. all of these are true for a neutral aqueous solution d. it has hydroxide and hydronium in equal concentrations e. it has a hydronium ion concentration of 1 x 10-7 M

According to the Bronsted-Lowry theory, what is the Bronsted-Lowry acid in the following equation, NH3 + H₂O <==> OH¯ + NH4+ The Bronsted-Lowry acid is H₂O The Bronsted-Lowry acid is OH The Bronsted-Lowry acid is NH3 The Bronsted-Lowry acid is NH4

Choose the process that will not disturb the following equilibrium. CO(g) + H₂O(g) CO₂(g) + H₂(g) A. removing CO₂ B. adding a catalyst C. decreasing the temperature D. adding H₂

H2CO3 ionizes as |H2CO3 = H+ + HCO3- K₁ = 4 x 10-6 HCO3 = H+ + CO32- K2 = 5 x 10-11 The correct information (s) related with 0.5 M Na₂CO3 solution is/are (A) The degree of hydrolysis of Na₂CO3 is 0.02 (approx.) (B) The pH of solution is 2.0 (approx.) (C) pOH of solution is 2.0 (approx.) (D) [H₂CO3] = 2.5 × 10-⁹ (approx.)