Chemistry College

below are three reactions showing how chlorine from CFCs (chlorofluorocarbons) destroy ozone (O3) in the stratosphere. Ozone blocks harmful ultraviolet radiation from reaching earth’s surface. Show how these 3 equations sum to produce the net equation for the decomposition of two moles of ozone to make three moles of diatomic oxygen (2 O3→ 3 O2), and calculate the enthalpy change. (6 points) R1 O2 (g) → 2 O (g) ΔH1°= 449.2 kJ R2 O3 (g) + Cl (g) → O2 (g) + ClO (g) ΔH2° = -126 kJ R3 ClO (g) + O (g) → O2 (g) + Cl (g) ΔH3°= -268 kJ

Answers

Answer 1

Answer:

ΔH = -338.8kJ

Explanation:

it is possible to sum the enthalpy changes of some reactions to obtain the enthalpy change of the whole reaction (Hess's law).

Using the reactions:

R₁ O₂(g) → 2O(g) ΔH₁°= 449.2 kJ

R₂ O₃(g) + Cl(g) → O₂(g) + ClO(g) ΔH₂° = -126 kJ

R₃ ClO (g) + O (g) → O₂ (g) + Cl (g) ΔH₃°= -268 kJ

By the sum 2R₂ + 2R₃:

(2R₂ + 2R₃) = 2O(g) + 2O₃(g) → 4O₂(g)

ΔH = 2ₓ(-126kJ) + (2ₓ-268kJ) = -788kJ

Now, this reaction + R₁

2O₃(g) → 3O₂(g)

ΔH = -768kJ + 449.2kJ

ΔH = -338.8kJ

Related Questions

Carbon-14 has a half-life of 5720 years and this is a fast-order reaction. If a piece of wood has converted 75 % of the carbon-14, then how old is it?

Answers

Answer:

11445.8years

Explanation:

Half-life of carbon-14 = 5720 years

First we have to calculate the rate constant, we use the formula :

Other Questions
The ratio of Ed's toy cars to Pete's toy cars was initially 5:2. After Ed gave 30 toy cars to Pete, they each had an equal number of cars. How many toy cars did they have altogether? You are a graduate student in the lab of a famous fly geneticist. You need to analyze a batch of mutant flies that were recently created in her laboratory to identify the single gene that is most likely mutated in each of the flies. Drag the mutations on the left to the appropriate blanks on the right to complete the sentences.a. knirps (a gap gene) b. hunchback (a gap gene) c. hedgehog (a segment-polarity gene) d. wingless (a segment-polarity gene) e. kruppel (a gap gene) f. even-skipped (a pair-rule gene) 1. Mutant fly F has predominantly lost abdominal structures, which is likely the result of a mutation in_____. 2. The wings are missing in mutant fly L, which is likely the result of a mutation in______. 3. Thoracic and abdominal structures are missing in mutant fly Q. The gene most likely responsible for this mutation is______. 4. Segment-sized sections of every other segment are missing in mutant fly Z. One likely candidate gene is_______. 5. Mutant fly X has lost the head and thorax. The gene most likely responsible for this mutation is_______. 6. The mutation observed in mutant fly O resulted in defects within the anterior or posterior regions of each segment. The gene that most likely caused this mutation is_______. Loren has a $200 annual (calendar year) deductible on her health insurance plan. By the end of 2018, she had paid $175 in medical expenses. On January 4, 2019 she went to the doctor for the first time that year and was charged $60 for an office visit. How much of that must she pay for herself The Walthers Company has a semi-annual coupon bond outstanding. An increase in the market rate of interest will have which one of the following effects on this bond?a. increase the coupon rate.b. decrease the coupon rate.c. increase the market price.d. decrease the market price.e. increase the time period. Surprise Delivery by Bart King Along with the crowd in the gym, Dave watched in amazement as Coach Harkins ran past the bleachers and out the door. "You've got to be kidding," Peyton said, wiping sweat off his forehead. "We're down one point. There are 10 seconds left in the game. And Coach's wife goes into labor now?" Derrick, the quietest kid on the team, set down his water bottle. "Wasn't her choice," he rumbled. "If you have to blame someone, blame the baby." The nursing instructor is conducting a teaching session on Lawrence Kohlberg's theory of moral development. The nursing instructor describes stage 4 as the child having more concern with society as a whole. which stage is being described?a) Law and order orientationb) Instrumental relativist orientationc) Universal erhical principles orientation d) Social contract and legalisric orientation An anchor lowered at a constant rate into the ocean takes 5 seconds to move -17.5 meters. What is the rate of the anchor in meters per second? A circular table top has a radius of 24 inches.What is the area of the table top, to the nearest square inch? Use 3.14 for n.75 in.2151 in.1809 in.27235 in.2 Buhao Construction currently is all-equity-financed. It has 17,000 shares of equity outstanding, selling at $100 a share. The firm is considering a capital restructuring. The low-debt plan calls for a debt issue of $270,000 with the proceeds used to buy back stock. The debt will pay an interest rate of 11%. The firm pays no taxes.a. What will be the debt-to-equity ratio if it borrows $220,000? (Do not round intermediate calculations. Round your answer to 2 decimal places.)Debt-to-equity ratio b. If earnings before interest and tax (EBIT) are $130,000, what will be earnings per share (EPS) if Reliable borrows $220,000? (Do not round intermediate calculations. Round your answer to 2 decimal places.)EPS $ c. What will EPS be if it borrows $420,000? (Do not round intermediate calculations. Round your answer to 2 decimal places.)EPS $ DIP LLC reports ordinary income (before guaranteed payments) of $120,000, rent expense of $40,000, and interest income of $4,000 for the year. In addition, DIP paid guaranteed payments to partner Percy of $20,000. If Percy owns a 40% capital and profits interest, how much income will he report for the year and what is its character? i attached the question in the image below Look at this chart of chronological events from Outcasts United. A flowchart of five boxes. Box 1 reads, Luma arrives at the center in a Volkswagen Beetle. Box 2 reads, Luma begins to coach the boys. Box 3 reads, Luma learns about the boys' past histories. Box 4 is blank. Box 5 reads, Luma quits Ashton's and opens a cleaning business. Which sentence best fills in the blank? Luma talks with Beatrice outside the apartment. Luma gives Jeremiah rides to every practice. Luma begins a team for fifteen-year-olds and under. Luma finds volunteer tutors for her players. A student remembers a long list of outdoor sculptures by imagining each piece on top of a different campus building, along Campus Drive. What memory strategy is being used? How much will Bob need to save each month if he wants to buy a $30,000 car with cash in 5 years? He can earn a nominal interest rate of 10% compounded monthly.a) $2.50b) $250.00c) $25.00d) $1,862.76 Solve the system of equations algebraically.{Y=(x-2)^2+2{Y+4=3x BRAINLIEST, 5 STARS, THANKS AND 100 POINTS IF ANSWERED BOTH CORRECTLY. --------------------- Which function rule describes the pattern in the table? X: -2, -1, 0, 1, 2 Y: 3, 2, 1, 0, -1 A) y = x + 1 B) y = x - 1 C) y = -x + 1 D) y = -x - 1 --------------------- Which function rule describes the pattern in the table? X: -2, -1, 0, 1, 2 Y: 14, 11, 8, 5, 2 A) y = 3x + 8 B) y = -3x - 8 C) y = 3x - 8 D) y = -3x + 8 -------------------- Thank you if you answered both correctly! Which side lengths form a right triangle? What is the purpose of academic writing A hotel salesperson enters sales in a text file. Each line contains the following, separated by semicolons: The name of the client, the service sold (such as Dinner, Conference, Lodging, and so on), the amount of the sale, and the date of that event. Write a program that reads such a file and displays the total amount for each service category. Display an error if the file does not exist or the format is incorrect. Choose the equivalent system of linear equations that will produce the same solution as the one given below 4x-y=-11 2x+3y=5