Compare and contrast the following hydrogen-storage technologies:

(1) compressed hydrogen; (2) liquid hydrogen; and (3) complex hydrides.

For the titration of 25.0 mL of 0.20 M hydrofluoric acid with 0.20 M sodium hydroxide , determine the volume of based added when pH is a) 2.85 b) 3.15 c)11.89

Outline of procedure:

Dilute bleach solution A 1/10.

Prepare analyte for titration by adding 10mL of diluted bleach solution, indicator and 5mL of 2 M HCl.

Titrate the analyte with 0.05524 M Na2S2O3.

Average volume of Na2S2O3 added = 31.25 mL

Question: Calculate the percent of sodium hypochlorite in the original bleach bottle using your averaged result. Show the calculation for solution A only. Which bleach solution is the more potent cleaning agent?

A large insulated bottle containing 703 mL of water initially at 21.5 degrees C is cooled by adding ice at 0 degrees C. Assume the specific heat of liquid water is constant at 4.18 kJkg K

(a) If 82 grams of ice is added to the bottle, what will the final temperature be? (Degrees C)

(b) How much ice must be added if the desired temperatue is 5.1 degrees C? (grams)

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Fundamentals of Instrumentation & Controls

Distillation is a process of continuous boiling and condensing used to separate mixtures of different fluids. A practical example of distillation is the separation of crude oil into multiple gases and liquids (propane, butane, naphtha, hexane, etc.). Components with higher boiling points (typically denser fluids) collect at the bottom of the tower, while components with lower boiling points (typically lighter fluids) and gases collect at the top of the tower.

In this distillation tower, the levels of liquid products at the bottom and top are being controlled. Explain how the control loops work

Drilling course.

List the advantages obtained by adding weighting material to mud?.

Phosphorus is diffused into a thick slice of silicon with no previous phosphorus in it. If the surface concentration of the phosphorus is 1 x 10^18 atoms/cm^3, and its concentration at 1 micrometer needs to be 1 x 10^15 atoms/cm^3, after a diffusion time of 1 hour. What is the temperature needed for the process?

Consider the following reaction: 3C2H5OH + 2 Na2Cr2O7 + 8H2SO4 à 3CH3COOH + 2Cr2(SO4)3 + 2Na2SO4 + 11 H2O

a) If a reactor is fed with a mixture having the following composition (in mol%): 20% de C2H5OH, 20% de Na2Cr2O7, and the balance H2SO4, which is the limiting reactant?

b) If 230 kg/h of C2H5OH are fed to the reactor, what is the amount (in kg/h) of the other two reactants that need to be fed to have a stochimetric feed?

Discuss in detail what is meant by reactive chemicals and explosives.

Ethanol, C2H6O, is most often blended with gasoline - usually as a 10 percent mix - to create a fuel called gasohol. Ethanol is a renewable resource and ethanol-blended fuels, like gasohol, appear to burn more efficiently in combustion engines. The heat of combustion of ethanol is 326.7 kcal/mol. The heat of combustion of 2-methylhexane, C7H16, is 1.150×103 kcal/mol. How much energy is released during the complete combustion of 324 grams of 2-methylhexane ? kcal Assuming the same efficiency, would 324 grams of ethanol provide more, less, or the same amount of energy as 324 grams of 2-methylhexane?

b. Combustion reactions are exothermic. The heat of reaction for the combustion of pentane, C5H12, is 838.7 kcal/mol. What is the heat of combustion for pentane in kcal/gram? kcal/gram How much heat will be given off if molar quantities of pentane react according to the following equation? C5H12 + 8 O2----------5 CO2 + 6 H2O _____ kcal

Determine the partial pressure of CO2 corresponding the transition between solid phases of Mg(OH)2(S) and magnesite MgCO3(S) in an open system open to CO2. Which solid phase will predominate at a 10-3.5 Atm pressure of CO2? The solubility products of Mg(OH)2 and MgCO3 are 10-10.7 and 10-7.5, respectively. The Henry constant of CO2 is 101.5 Atm·L·mol-1

500 kgmol/h of a gas stream containing 2% of component A is to be purified using gas absorption. The vent from the absorber can contain no more than 0.5 kgmol/h of A. Two scrubbing liquids, P and Q, are available.

a. For liquid Q, m=0.45. How many stages are required in the scrubber for 1.5 times the minimum liquid rate? The incoming Q contains no A. 2

b. For liquid P, m=0.25. If liquid P is used in the scrubber specified in part a, at the same rate as Q is used in part a, what recovery can be achieved? The incoming P contains no A.

c. How would the answer to b change if the incoming P contains 0.1% A?

2500 mol/min of a liquid stream containing 1% component B is to be treated by stripping with air. The incoming air contains 0.01% B, and the liquid leaving the stripper is to contain 0.01% B. The Henry’s law constant is 1.5.

a. What is the minimum required gas rate?

b. If the gas rate is 1.15 times the minimum gas rate, how many theoretical stages are required?

An exhaust stream contains 1250 ppm of a toxic impurity that is to be removed by adsorption into a clean liquid; the absorber vent must contain no more than 15 ppm of the impurity. The Henry’s law constant is 0.5.

a. If the gas rate is 7.40 kmol/h, how many theoretical stages are required, and what liquid rate is required, if the absorber operates at 1.35 times the minimum liquid rate?

b. If the gas rate increases to 8.10 kmol/h but still contains 1250 ppm of the impurity, what will the concentration of the impurity of the scrubber vent be? Use the liquid rate and number of stages from part a.

c. If the gas rate increases to 8.10 kmol/h (with 1250 ppm of the impurity), what liquid rate will be required to reduce the concentration in the absorber vent to 15 ppm using the number of stages determined in part a?