Equilibrium Questions and Answers

A chemistry student weighs out 150. g of an unknown solid compound X and adds it to 450. mL of distilled water at 20.° C. After 10 minutes of stirring, only some of the X has dissolved. The student drains off the solution, then washes, dries and weighs the X that did not dissolve. It weighs 60. g. Using only the information above, can you calculate the solubility of X in water at 20.° C ? If you said yes, calculate it. Be sure your answer has a unit symbol and 2 significant digits. yes no 0 0x10 ☐☐ X I 00 Ś 4 ?

A 90.0 g piece of metal with specific heat 0.622- final temperature of the water? J for the specific heat of water. 8°C • Use 4.184 Select the correct answer below: O 21.5°C O 23.5°C O 33.0°C J and at 101°C is placed in 300. g of water at 27.0°C. What will be the g°C O 30.2°C

A student combined a 2.0 x 10-3 mol/L solution of lead nitrate, Pb(NO3)2(aq), with a 1.0 x 10-3 mol/L solution of hydrochloric acid, HCl(aq), in equal volumes (so there's no need to find a final volume). Their calculations so far are shown in the image provided. Will a precipitate of lead chloride, PbC12(s), form? Support your answer by including all relevant calculations and assumptions. (6 marks) HINT: Find the trial ion quotient. *SHOW YOUR WORK! K PbCl₂ (s) Ksp = 1.6 × 10-5 * Overall equation. Pb(NO3)2(aq) + HCl(aq) = PbCl₂(s) + HNO3(aq) *used solubility table Dissociation equations. Pb(NO3)2(aq) = Pb²+(aq) + 2 NO3(aq) HCl(aq) = H+ (aq) + Cl(aq)

A geochemist in the field takes a small sample of the crystals of mineral compound X from a rock pool lined with more crystals of X. He notes the temperature of the pool, 18.° C, and caps the sample carefully. Back in the lab, the geochemist dissolves the crystals in 2.00 L of distilled water. He then filters this solution and evaporates all the water under vacuum. Crystals of X are left behind. The researcher washes, dries and weighs the crystals. They weigh 0.10 kg. Using only the information above, can you calculate the solubility of X in water at 18.º C? If you said yes, calculate it. Be sure your answer has a unit symbol and 2 significant digits. yes 0 no 0.0 X μ 00 ?

2CO(g) + O₂(g) = 2CO₂(g) The equilibrium constant Kc of above reaction is 0.5. If one mole each of gases CO, O2 and CO2 are subjected for reaction in a one liter vessel, the reaction will move towards forward direction backward direction both direction unpredictable

The acid dissociation constant of HPO42 2- 4²- is less than the acid dissociation constant of H₂PO4. This is because O it's harder to remove an H+ from H₂PO4 than from HPO4²- bases are always weaker than acids O it's harder to remove the H+ from HPO42- than from H₂PO4 - 2- OHPO4²- is part of a buffer system

Two different proteins X and Y are dissolved in aqueous solution at 37 °C. The proteins bind in a 1:1 ratio to form XY. A solution that is initially 1.00 mM in each protein is allowed to reach equilibrium. At equilibrium, 0.25 mM of free X and 0.25 mM of free Y remain. What is Kc for the reaction?

AGAIN, consider the following equation: 3NaOH(aq) + FeCl3(aq) --> Fe(OH)3(s) + 3NaCl(aq) If a chemist combines 5.50 moles of NaOH and 2.75 mols of FeCl3, what would be the theoretical yield of Fe(OH)3(s) in moles? Round your answer to the proper number of significant figures, do not include units.

Initially, only A and B are present, each at 2.00 M. What is the final concentration of A once equilibrium is reached? Express your answer to two significant figures and include the appropriate units.

Given f(x) = 7x and g(x) = 3x² + 7, find the following expressions. (a) (fog)(4) (b) (gof)(2) (c) (fof)(1) (d) (gog)(0) (a) (fog)(4)= (Simplify your answer.) (b) (gof)(2) = (Simplify your answer.) (c) (fof)(1) = (Simplify your answer.)

Given the two reactions 1. H₂S(aq)<-> HS¯(aq) + H+ (aq), K₁=9.73x10-8, and 2. HS (aq) = <->S2-(aq) + H+ (aq), K₂ = 1.47x10-19, what is the equilibrium constant Kfinal for the following reaction? S2 (aq) + 2H+ (aq) <-> H₂S(aq) Enter your answer numerically.

For each of the following compounds, decide whether the compound's solubility in aqueous solution changes with pH. If the solubility does change, pick the pH at which you'd expect the highest solubility. You'll find K,, data in the ALEKS Data tab. compound PbCl₂ KCI BaCO, Does solubility change with PH? Oyes no O yes Ono O yes no pH = 6 O highest solubility pH = 7 O pH = 9 O XS ?

<-4 A chemistry graduate student is given 125. mL of a 0.40 M dimethylamine ((CH3)₂NH) solution. Dimethylamine is a weak base with K, -5.4 × 10. What mass of (CH3)₂NH₂Cl should the student dissolve in the (CH₂), NH solution to turn it into a buffer with pH = 11.18? You may assume that the volume of the solution doesn't change when the (CH3)2NH₂Cl is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits. C

A chemistry graduate student is given 125. mL of a 0.40 M dimethylamine ((CH3)₂NH) s solution. Dimethylamine is a weak base with K-5.4×10. What mass of (CH3)2NH₂ CI should the student dissolve in the (CH3)₂NH solution to turn it into a buffer with pH = 11.18? You may assume that the volume of the solution doesn't change when the (CH3)₂NH₂Cl is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.

QUESTION 6 1 POINT A solution has a concentration of 0.87 M KBr and a volume of 0.020 L. It is then diluted to a concentration of 0.29 M. What is the new volume? Select the correct answer below: 0.30 L O 0.060 L O 0.020 L O 0.0070 L 8

A chemistry graduate student is given 100. mL of a 1.10 M nitrous acid (HNO₂) solution. Nitrous acid is a weak acid with K =4.5 × 10. What mass of KNO₂ should the student dissolve in the HNO₂ solution to turn it into a buffer with pH =2.78? You may assume that the volume of the solution doesn't change when the KNO₂ is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.

In lab you titrate 45.00 mL of Ca(OH)2 with 30.08 mL of 1.45 M HBr. What do you determine the molarity of the Ca(OH)2 to be? Ca(OH)2 (aq) + 2 HBr (aq) → 2 H₂O ( CaBr2 (aq)

Phase changes always occur with a change in the average amount of heat in a system. Heat, which is a measure of energy, either is absorbed by the material during a phase change or is released by the material during the phase change. However, although the heat content of the material changes, the temperature does not change during a phase change. Classify the following phase changes as processes that require the input of energy, or as processes that have a net output of energy.

A chemist dissolves 727. mg of pure perchloric acid in enough water to make up 370. mL of solution. Calculate the pH of the solution. Be sure your answer has the correct number of significant digits.

Determine the [OH-], pH, and pOH of a solution with a [H+] of 5.2 x 10-¹0 M at 25 °C. Determine the [H], pH, and pOH of a solution with an [OH-] of 4.3 x 10-¹¹ M at 25 °C.

Suppose a 0.021 M aqueous solution of phosphoric acid (H₂PO₂) is prepared. Calculate the equilibrium molarity of HPO You'll find information on the properties of phosphoric acid in the ALEKS Data resource. Round your answer to 2 significant digits.

A chemist titrates 180.0 mL of a 0.5163 M acetic acid (HCH, CO₂) solution with 0.7728 M NaOH solution at 25 °C. Calculate the pH at equivalence. The PK of acetic acid is 4.76. Round your answer to 2 decimal places. Note for advanced students: you may assume the total volume of the solution equals the initial volume plus the volume of NaOH solution added.

Suppose a 0.42 M aqueous solution of phosphoric acid (H₂PO4) is prepared. Calculate the equilibrium molarity of HPO4. You'll find information on the properties of phosphoric acid in the ALEKS Data resource.

An analytical chemist is titrating 246.1 mL of a 0.8100 M solution of methylamine (CH3NH₂) with a 0.4000 M solution of HNO3. The p K, of methylamine is 3.36. Calculate the pH of the base solution after the chemist has added 370.0 mL of the HNO3 solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of HNO3 solution added.

An unknown metal, M, makes a precipitate with sulfate having the chemical formula M SO. At equilibrium, the concentration of the metal ion is 0.000795 M and the sulfate ion concentration is 0.0003975 M. What is the K of the metal sulfate?

Which of the following statements about acid strength is true? The stronger the acid, the further the equilibrium lies to the left. The stronger the acid, the smaller the Ka- The stronger the acid, the smaller the pka. The stronger the acid, the larger the pka-

An analytical chemist is titrating 68.9 mL of a 0.2300 M solution of isopropylamine ((CH₂)₂CHNH₂) with a 0.3700 M solution of HNO 3. The P K of isopropylamine is 3.33. Calculate the pH of the base solution after the chemist has added 19.0 mL of the HNO3 solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of HNO3 solution added.

An analytical chemist is titrating 109.0 mL of a 0.1700 M solution of diethylamine ((C₂H₂)₂NH) with a 0.3200 M solution of HIO3. The PK, of diethylamine is 2.89. Calculate the pH of the base solution after the chemist has added 67.5 mL of the HIO3 solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of HIO3 solution added.

A 1000 mL solution contains 0.450 M K₂CrO and 0.450 M Na₂SO4. A concentrated Ba(NO3)₂ is slowly added to the solution. What is the barium ion concentration at the point when a precipitate just starts to form? (Ksp BaCrO4 = 8.5×10-¹¹ and Ksp BaSO4=2.3×108)

At a particular temperature, aluminum hydroxide, Al(OH)3, has a Ksp = 5.94×10-25. What is the hydroxide ion concentration in a saturated aluminum hydroxide solution? [OH-] = M

In general, which of the following will 5 points have the largest value? A. Equilibrium constant for the solubility of an insoluble salt, B. Equilbrium constant for the formation of a complex ion, K C. Equilibrium constant for the auto-ionization of water, K D. Second acid dissociation constant, K E. Equilibrium constant for the dissociation of a complex ion, K

Suppose a 0.040 M aqueous solution of sulfuric acid (H₂SO4) is prepared. Calculate the equilibrium molarity of SO42-. You'll find information on the properties of sulfuric acid in the ALEKS Data resource. Round your answer to 2 significant digits.

Green tea has a pH around 8.2, what is the [OH-] and is this acidic or basic? K₁ = [H3O+][OH-]; pH = -log[H3O+]; [H3O+]=10-PH 6.31 x 10; acidic 6.31 x 10 M; basic 1.58 x 10-6 M; acidic 1.58 x 106 M; basic

A chemist titrates 170.0 mL of a 0.7119 M hydrocyanic acid (HCN) solution with 0.5577 M NaOH solution at 25 °C. Calculate the pH at equivalence. The PKa ,of hydrocyanic acid is 9.21. Round your answer to 2 decimal places. Note for advanced students: you may assume the total volume of the solution equals the initial volume plus the volume of NaOH solution added.

In the atmosphere, the concentration of N₂ is 0.033 M and the concentration of O₂ is 0.00810 M at 25°C. Suppose the concentration of NO(g) in the atmosphere is 1.13 × 10-¹7 M at 25°C. What is the equilibrium constant for this reaction at 25°C? Type the correct answer in the box. Express your answer to two significant figures. Keq=10-31

The pH of Cherry Coke is 2.52, what is the [H3O+] and is this acidic or basic? K₁ = [H3O+][ OH]; pH = -log[H3O+]; [H3O+] =10-PH 3.3 x 10-12 M; basic 3.0 x 10-3 M; acidic 3.3 x 10-12 M; acidic 3.0 x 10-3 M; basic

The acid dissociation K of propionic acid (C₂H5CO₂H) is 1.3 × 10-5. Calculate the pH of a 1.5 x 10 M aqueous solution of propionic acid. Round your answer to 2 decimal places.

What is the net ionic equation for the reaction of AgNO,(aq) and Na₂CO (aq)? a. Ag+(aq) + CO3²-(aq) → AgCO(s) b. Na+(aq) + NO3-(aq) → NaNO,(s) c. 2Ag+(aq) CO32-(aq) → Ag;CO,(s) d. AgNO3(aq) + Na₂CO3(aq) → 2NaNO,(aq) + Ag CO₂ (s)

The reaction between strontium hydroxide and chloric acid produces a. a molecular compound and a weak electrolyte b. two weak electrolytes c. two strong electrolytes d. a molecular compound and a strong electrolyte

An analytical chemist is titrating 173.5 mL of a 0.6900 M solution of propionic acid (HC₂H,CO₂) with a 1.200 M solution of KOH. The P K of propionic acid is 4.89. Calculate the pH of the acid solution after the chemist has added 119.5 ml. of the KOH solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of KOH solution added. Round your answer to 2 decimal places.

A chemistry graduate student is given 500. mL of a 0.90 M dimethylamine ((CH3)₂NH) solution. Dimethylamine is a weak base with K, -5.4 × 10. What mass of (CH₂)₂NH₂Br should the student dissolve in the (CH₂), NH solution to turn it into a buffer with pH -10.87? You may assume that the volume of the solution doesn't change when the (CH3)₂NH₂ Br is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.

A chemistry graduate student is given 125. mL of a 1.30 M diethylamine ((C₂Hs), NH) solution. Diethylamine is a weak base with K-1.3×10. What ass of (C₂H₂)₂NH₂ Br should the student dissolve in the (C₂H₂)₂NH solution to turn it into a buffer with pH-10.95? You may assume that the volume of the solution doesn't change when the (C₂H₂)₂NH₂ Br is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.

A chemistry graduate student is given 100. mL of a 0.10 M hydrocyanic acid (HCN) solution. Hydrocyanic acid is a weak acid with K-4.9 x 10¹0. What mass of NaCN should the student dissolve in the HCN solution to turn it into a buffer with pH = 8.96? You may assume that the volume of the solution doesn't change when the NaCN is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.

What is the percent yield of calcium nitride for this reaction? 3Ca(s) + N₂(g) →Ca3N₂ (s)

The mixing of which pair of reactants will result in a precipitation reaction? See solubility table above. K2SO4(aq) + Cu(NO3)2(aq) Na3PO4 (aq) + KCI (aq) NH4Br(aq) + NH4l(aq) Zn(NO3)2(aq) + Na2CO3(aq) NaClO4(aq) + (NH4)2S(aq)

A chemist dissolves 417. mg of pure potassium hydroxide in enough water to make up 150. mL of solution. Calculate the pH of the solution. (The temperature of the solution is 25 °C.)

An analytical chemist is titrating 233.3 mL of a 1.200 M solution of cyanic acid (HCNO) with a 0.7500 M solution of NaOH. The P K of cyanic acid is 3.46. Calculate the pH of the acid solution after the chemist has added 232.9 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.

A chemist dissolves 620. mg of pure hydrochloric acid in enough water to make up 140. mL of solution. Calculate the pH of the solution. Round your answer to 3 significant decimal places. 0 0.9 X S ?

A concentrated solution of 0.138 M sodium phosphate is used to make a dilute solution with a sodium ion concentration of 1.72 x 10-2 M. The dilute solution is prepared by removing 64.8 mL of 0.138 M sodium phosphate and diluting it by adding water to make a 1. 72 x 10-2 M sodium ion concentration. What is the total volume of the dilute solution? 00 (A) 2.69 mL (B) 1.45 x 10³ mL (C) 1.36 x 10³ mL (D) 8.08 mL (E) 1.56 x 103 mL

A chemist dissolves 436. mg of pure hydrobromic acid in enough water to make up 280. mL of solution. Calculate the pH of the solution. Round your answer to 3 significant decimal places.