1 a) Water can decompose to hydrogen and water vapor at high temperatures. You're pondering a little
this and suggests the following mechanism:
?₂? → ?? + ? Ka
? + ? → ?₂ Kb
?? + ?? → ?₂?₂ Kc
?₂?₂ → ?₂ + ?₂ Kd
From this information, derive an expression of the hydrogen formation rate. Don't forget to clearly state any assumptions you make.

b) Suggest what information could be used to either support the mechanism or reject it. Don't forget to justify your suggestions.

c) You realize that the first reaction must be able to go the other way too. Would this affect yours proposed mechanism in any way? Note that you do NOT have to derive a new expression, but well motivate your answer.

1 a) Determine the enthalpy change for the following reaction under standard conditions and 25 ° C:
2Hg (l) + Cl₂ (g) → Hg₂Cl₂ (s)
enthalpy for : Hg (l) = 0
  Cl₂ (g) = 0
Hg₂Cl₂ (s) = -265.22
b) The entropy change is for the reaction is -182.61 J K-1 mol-1 at standard conditions and 25 ° C. Is the reaction spontaneous under standard conditions and 25 ° C?
c) What will be the enthalpy change at 100 ° C?

What's the objective of precursor preparation experiment?

And why the color of precursors changes during the experiment?

A 4,500 litre tank contains 2,500 litres of brine. There is 50 kg of salt initially present. Pure water is being put into the tank at 20 litres/min. Brine solution is draining away at a rate of 15 litres/min.
a)Create a mathematical model of the dissolved salt in the solution. Give amount of salt in terms of time (t).
b)Calculate how much salt is in the system after 15 minutes. State all of the assumptions that you are using.
c)Create a working MATLAB program which deploys your mathematical model above. It is important to show the steps that you have chosen to create your mathematical model of this system.

(C2H5OH) is a common alcohol used in food, beverage and pharmaceutical industries. The production of ethanol is through fermentation of glucose (C6H12O6) in a reactor, which produces ethanol and carbon dioxide (CO2). Unfortunately, glucose fermentation also produces propenoic acid (C2H3CO2H) and water (H2O) in a side reaction. A production engineer is designing a glucose fermentation process that produces 46 000 kg of ethanol. The conversion of glucose in this process is 80 % and the selectivity of ethanol production to propenoic production is 20. (Atomic mass : C = 12, H = 1, O = 16) (a) Write stoichiometric equations for the main and side reactions of the process. (b) Draw and label completely the process flow diagram of this process. (c) Calculate the degree of freedom for this process based on Extent of Reaction method. (d) Using Extent of Reaction method, determine the amount of feed (kg) and molar composition of the product stream (%). (e) Determine the yield of ethanol in the designed process.

Q2 (a) Discuss the importance of reaction orders, reaction rates and reaction rates as a function of temperature. (b) Reactant M decomposes in gas phase at 850oC and 4.6 bar according to the reaction in (2a) while the first order rate is given by (2b). Calculate the reaction volume that will yield 95% conversion of feed consisting of 3Moles of M per hour. Assume the reaction takes place in PFR, C is concentration of M. M(g)→P(g) + 6W(g) (2a)

-r=10/hrs (2b)

question one 100 kg of a gas has the following mass composition: 19.3% CO2, 6.5% O2 , 2.1% H2O and 72.1% N2

What is the mole fraction of each component in the mixture?

Molecular weight of (CO2= 44, O2=32, H2O=18, N2=28)

question two The density of a certain solution is 1.05 g/cm3 at 25°C. How many cubic meters will be occupied by 5000 kg of this solution.

1. After having dinner at a fancy restaurant furnished with navy blue table runner, you notice the sleeves of your white wool jacket has turned blue. What do you think caused this to happen? What standard test method would you use to evaluate the color?

Why are reactors often operated adiabatically instead of isothermally? How can you keep a reactor adiabatic?

It is desired to cool down (0.37) kg/s of an aqueous solution with a heat capacity similar to water from 60 to 50^oC. The cooling fluid will be (0.33) kg/s of water at 25^oC. A double-pipe heat exchanger will be used. The external diameter of the interior tube is 0.025 m. The overall heat transfer coefficient is estimated as 1,600 W/(m^2.K). Calculate the necessary tube length if:

1. A countercurrent arrangement is used.
2. A co-current arrangement is used.

When molasses is fermented to produce a liquor containing ethanol, a CO2-rich vapor

containing a small amount of ethanol is evolved. The alcohol will be recovered by

countercurrent absorption with water in a packed-bed tower. The gas will enter the tower at a

rate of 180 kmol/h, at 303 K and 110 kPa. The molar composition of the gas is 98% CO2 and

2% ethanol. The required recovery of the alcohol is 97%. Pure liquid water at 303 K will enter

the tower at the rate of 151.5 kmol/h. Estimate the packed height required to recover 97% of

the alcohol. The system ethanol-CO2-water at the given temperature and pressure obeys

Henry’s law with m=0.57. The diameter of the tower is 0.738 m and ky’a=0.191 kmol/m3 and

3 kx’a=0.402 kmol/m .

(a) Discuss the structures and properties of Austenite and duplex stainless steels with reference to typical applications. [12 Marks]

(a) Explain the major differences between producer gas and water gas.

(b) Explain why the presence of even a small amount of H2 can substantially expedite the reaction of CO-O2 mixture by using chemical kinetics analysis.

Suggest the best instrumental method(s) for the following analyses. Also suggest possible sample pre-treatment methods or accessaries if there are any. Consider the sample concentration, possible interferences, sample size, etc.

6) To measure the concentration (about 10-3 M) of Cu2+ samples. 7) To know the crystalline structure of solid samples.

8) To measure Ca2+ concentration (about 1 ppm); the sample volume is very small.

9) To know the molecular structure of a carbonyl-containing organometallic compound [M(CO)n].

10) Roughly estimate the elemental composition of chemical compounds.

1) Mercury (Hg) can be used in a barometer to measure air pressure, based on how tall a column of mercury can be supported by the pressure of the atmosphere or another gas sample. The barometric reading taken at Skyline College on a specific day was 743.8 mm Hg. If the interior circumference of the tube holding the mercury is 9.82 mm, what is the mass of mercury in the tube (above the pool of mercury)? The column may be treated as a cylinder. Mercury has a density of 13.55 g/mL.

2) What is the length (in cm) of the side of an iron ingot (rectangular box) that has a mass of 4.578 kg and has width = height = 5.00 cm

3) What will be the final volume when a 98.356-g sample of lead (Pb) shot is added to a graduated cylinder holding 24.7 mL of water?