Methane, a powerful greenhouse gas, is generated via the anaerobic decomposition of solid waste in landfills. Collecting the methane for use as a gaseous fuel rather than allowing it to be released to the atmosphere provides an alternative to natural gas as an energy source and has a beneficial effect on the environment. If a batch of waste with mass M(tonnes) [1 tonne or 1 metric ton = 1000 kg] is deposited in a landfill at t=0, the rate of generation of methane at a later time t is given by the following equation V CH4 (t) = kL o M waste e -kt where: V CH4 (SCM CH 4 /y) = methane generation rate [SCM = m 3 (STP)] K = rate constant (y -1 ), a measure of how fast the waste decomposes L o = landfill gas yield potential [SCM CH 4 /tonne waste] M waste = tonnes of waste deposited at t= 0
a. Explain in your own words the benefits of reducing the release of methane from landfills and using the methane as a fuel instead of natural gas.
b. Starting with the above equation, derive an expression for the mass generation rate of M CH4 (t)[tonnes CH 4 /y]. Without doing any calculations, sketch the shape of a plot of M CH4 vs t from t=0 to t = 3y, and graphically show on the plot the total masses of methane generated in YEARS 1, 2, and 3 (Hint: Remember your calculus.) Then derive an expression for M CH4 (t)(tonnes CH 4 ), the total methane generated from t =0 to an arbitrary time t.
c. A new landfill has a yield potential L o = 100 SCM CH 4 /tonne waste and a rate constant k = 0.04y -1 . At the beginning of its first year, 48,000 tonnes of waste are deposited. Calculate the tonnes of methane generated from this deposit over a three-year period.
d. A junior engineer solving the problem of Part c calculates the methane produced in three years from the 48,000 waste deposit as M CH4 (t=3) = M CH4 (t=0){tonnes CH 4 /y}x 1y + M CH4 (t=1)x1 + M CH4 (t=2)x1 where M CH4 is given by the first expression derived in Part b.
-- -- -- Briefly state what the engineer is assuming about the rate of methane generation
-- -- -- - Calculate the value she would determine and the percentage error in her calculation, and show graphically what the calculated value corresponds to on another sketch of M CH4 vs t.
-- -- - The answer to Part c is 390 tonnes CH 4 . When one of the text authors first did the calculation of M, the result was 210 tonnes CH 4 . The author immediately knew that something had to be wrong in the calculation. Explain her reasoning.
e. The following amounts of waste are deposited in the landfill on January 1 in each of three consecutive years: Waste (tonnes) Year 1 48,000 Year 2 45,000 Year 3 54,000 Calculate the metric tons of methane generated through December 31 of the third year.
f. One way to avoid the environmental hazard of methane generation is to incinerate the waste before it has a chance to decompose. What problems might this alternative process introduce?

How many milliliters of 4.7 M HCl must be added to 3.9 L of 0.11 M K₂HPO₄ to prepare a pH = 7.44 buffer?

Consider the following reaction at 283 K:

2A + B → C + D

where rate = k[A][B]². An experiment was performed where [A]_o = 2.67 M and [B]_o = 0.00241 M. A plot of 1/[B] vs. time has a slope of 10.01. What will the rate of this reaction be when [A] = [B] = 0.345 M?

A 240.0-mL sample of spring water was treated to convert any iron present to Fe²⁺. Addition of 27.00-mL of 0.002520 M K₂Cr₂O₇ resulted in the reaction

6Fe²⁺ + Cr₂O₇^2- + 14H⁺ ----> 6Fe³⁺ + 2Cr³⁺ + 7H₂O

The excess K₂Cr₂O₇ was back-titrated with 8.80 mL of 0.00936 M Fe²⁺ solution. Calculate the concentration of iron in the sample in parts per million.

Concentration of iron = _______ ppm?

Histidine has ionizable groups with pKa values of 1.8, 6.0, and 9.2, as shown below. A biochemist makes up 100 mL of a 0.100 M solution of histidine at a pH of 5.40. She then adds 40 mL of 0.10 M HCl. What is the pH of the resulting solution?

ssume you dissolve 0.235 g of the weak acid benzoic acid, C6H5CO2H, in enough water to make 4.00 ✕ 102 mL of solution and then titrate the solution with 0.163 M NaOH. C6H5CO2H(aq) + OH-(aq) C6H5CO2-(aq) + H2O(ℓ) What are the concentrations of the following ions at the equivalence point? Na+, H3O+, OH- C6H5CO2- M Na+ M H3O+ M OH- M C6H5CO2- What is the pH of the solution?

Calculate the molarity of a 1.8 L solution that contains 6.71 moles of NaCl. How many moles of NaOH are in a 935 mL solution that has a concentration of 7.3 M?

What is the volume (in L) of a solution that contains 3.8 moles of MgCl2 and has a concentration of 2.5 M? When you use 58.9 mL of 4.0 M HCl to produce H2 gas, how many grams of zinc does it react with? 2HCl + Zn → ZnCl2 + H2

How many moles of NaOH are in a 1438 mL solution that has a concentration of 1 M?

The decomposition of XY is second order in XYand has a rate constant of 7.20

A) For Gorilla glass, Xensation, Sapphire glass, and Dragontrail glass, tabulate their composition, how they are made and processed, their hardness, strength, and cost.? Please, no English (Merican) units.

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Answer the question in clear words and in very good description!!! Please type your answer. Thanks

So let’s say you have a beaker that contains 78.8g of ammonium carbonate and to this you add 175 mL of 5.80 M hydrochloric acid according to the following chemical equation:

2HCl(aq) + (NH4)2CO3(s) -- > 2NH4Cl(aq) + H2O(l) + CO2(g) .DeltaH = -145 kJ

A) Draw the beaker at the end of the reaction - what would e in the beaker and/or around it. What would the products look like on a molecular/atom/ion level?

B) Why would water vapor pressure be involved in this reaction?

C)At STP, how many L of the gas is produced? (Ignoring water vapor)

D) Assuming the volume given in the problem remains the same, what is the molarity of the ionic compound in the reaction at the end of the reaction?

E) How many moles of excess reactant are left over at the end of the reaction?

F) How many L of your gas would be produced if the reaction was done at 25C at 0.992atm?

What is the pH of solution if 40 mL 0.1 M HCl is mixed with 60 mL 0.2 M HAc?

29) What is the stoichiometric coefficient for oxygen when the following equation is balanced using the lowest whole-number coefficients? ________ C3H6O2(l) + ________ O2(g) →________ CO2(g) + ________ H2O(l) A) 5 B) 7 C) 1 D) 3 29)

30) Which of the following underlined items is not an intensive property? A) the melting point of iron metal B) the color of copper hydroxide C) the amount of gold. D) the density of argon 30)

31) Rubidium belongs to the ________ group of the periodic table. A) alkali metal B) alkaline earth metal C) halogen D) noble gas 31)

32) Chlorine belongs to the ________ group of the periodic table. A) alkali metal B) alkaline earth metal C) halogen D) noble gas 32)

33) An element has two naturally occurring isotopes. One has an abundance of 37.4% and an isotopic mass of 184.953 amu, and the other has an abundance of 62.6% and a mass of 186.956 amu. What is the atomic weight of the element? A) 185.954 amu B) 186.956 amu C) 185.702 amu D) 186.207 amu 33)

34) A piece of metal ore weighs 7.25 g. When a student places it into a graduated cylinder containing water, the liquid level rises from 21.25 mL to 25.00 mL. What is the density of the ore? A) 1.93 g/mL B) 3.21 g/mL C) 0.141 g/mL D) 0.281 g/mL 34)

4 35) How many protons (p) and neutrons (n) are in an atom of 226 88 Ra? A) 138 p, 88 n B) 88 p, 226 n C) 226 p, 88 n D) 88 p, 138 n 35)

36) 1.00 mole of O2 contains the same number of molecules as A) 0.667 mole of O3. B) 1.00 mole of CH3CO2CH2Cl. C) 2.00 mole of CH3CH2OCH2Br. D) All of these 36)

37) What is the number of moles of 5.00 × 10 22 molecules of NaBr? A) 0.083 moles B) 1.0 moles C) 1.2046 moles D) 0.037 moles 37)

) 39) Na2S is named A) sodium(II) sulfide. B) sodium disulfide. C) sodium sulfide. D) sodium sulfur. 39) 40) The factor 10-3 corresponds to which prefix? A) centi B) deci C) deka D) milli 40)

41) A sample of pure calcium fluoride with a mass of 15.0 g contains 7.70 g of calcium. How much calcium is contained in 35.0 g of calcium fluoride? A) 18.0 g B) 15.0 g C) 1.99 g D) 7.70 g

I am struggling with Mechanism problems in my organic Chemistry 1 class. Can you explain how SN1, SN2, E1 and E2 play a role in mechanisms and everything else that is involved with a mechanism problems (like maybe doing a practice problem and explaining it step by step would be a big help). Thank you!!!!!

Why is a photomultiplier tube not used as a detector at infrared wavelengths?