Analysis of a 2.016 g sample of pure magnesium oxide gave 1.216 g magnesium and 0.800 g of oxygen. A second sample weighing 4.479 g was found to contain 2.701 g magnesium and 1.776 g oxygen. Show that these data are in agreement with the law of definite composition.
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1. Why would it be beneficial to slow down the rate of a very fast reaction? Give at least one example of a fast reaction that is slowed down. Provide at least one citation for this question. ?
2. What does order mean when discussing kinetics? Discuss the difference between zero, first, and second order reactions and how order can be determined for a reaction. Provide at least one citation for this question. ?
3. If the rate constant is independent of analytical wavelength, why is it still beneficial to use the maximum absorbance wavelength for data collection? ?
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4. The horizontal wye fitting in the figure splits the 20?C water flow rate equally. Inlet volumetric flow rate is 5 ft3/s and inlet pressure is 25 lbf/in2 (gage). In each branch water flow rate is split equally. If energy losses are neglected, estimate pressure of water leaving second and third branch. What is the vector force required to keep the wye in place?
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Biochemical oxygen demand i.e. BOD) is a measure of the potential damage that can be done to the dissolved oxygen content of a body of water by organic waste. A BOD is also the amount of O2required to degrade or decompose the wastes. Its name comes from the "demand" that organic carbon has for O2 through biochemical (enzyme) oxidation. BOD – demanded oxygen – can be likened to a debt that must be paid. Dissolved oxygen (DO) can be thought of as the currency used to pay the debt. If DO (assets) exceeds BOD (debt), aerobic conditions (economic solvency) will prevail. If BOD exceeds DO, bankruptcy may ensue. Bankruptcy, in this case, is the depletion of water's chief asset, O2. Over a period of time, the water's oxygen level is usually replenished by oxygen from the air. The length of this time period depends on the severity of the initial loss of oxygen. If we assume that the part of the organic waste that is being degraded is carbon, C ( a good assumption), then we can write the following chemical formula: C + O2 ? CO2 If we were to do a mass analysis (i.e. gram for gram, pound for pound, etc.) of this equation, we would find that for every 3 parts of C, we would need 8 parts of O2. If you're thinking that it looks like it should be a one for one deal, you're absolutely correct. It does in fact require one MOLECULE of carbon to react with one MOLECULE of oxygen, but if we would weigh those molecules we'd see that different molecules weigh different amounts and therefore based on mass, we'd get the 3:8 ratio. Do not overthink this problem. If you think along the lines of a is to b as x is to y, you'll be on the right track. Enter ONLY the answer in the provided answer box. QUESTION 1 Consider a small lake, 0.3 miles across and 8 ft deep, that contains a total of 40 tons of dissolved oxygen. Calculate the BOD (i.e.calculate the amount of oxygen required to degrade the amount of organic waste given) if 6 tons of carbon-based waste is dumped into the lake. Round your answer to zero places past the decimal. Question 2 Repeat the BOD calculation as done in #1, but this time let's dump in 32 tons of carbon-based waste. Round your answer to zero places past the decimal. QUESTION 3 The differences between the two cases above include all of the following: (Select all that apply)
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A well-insulated tank of 50 m3 volume initially contains 16,000 kg of water distributed between liquid and vapor phases at 25°C. Saturated steam at 1500 kPa is admitted to the tank until the pressure reaches 800 kPa. What mass of steam is added (kg)?
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Reliability is a concept that should be understood in the development of systems. Discuss the difference between series and parallel (redundant) networks and how such networks can increase or decrease total reliability of the system.
Discuss the FMECA process its components, purpose and how it relates to system reliability.
Maintainability and maintenance are important and related to each other. Describe each and the relationship to each other.
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The small bubbles that form on the bottom of a water pot that is being heated (before boiling) are due to dissolved air coming out of solution.
Part A
Use Henry's law and the solubilities given below to calculate the total volume of nitrogen and oxygen gas that should bubble out of 1.1 L of water upon warming from 25 ?C to 50 ?C. Assume that the water is initially saturated with nitrogen and oxygen gas at 25 ?C and a total pressure of 1.0 atm. Assume that the gas bubbles out at a temperature of 50 ?C. The solubility of oxygen gas at 50 ?C is 27.8 mg/L at an oxygen pressure of 1.00 atm. The solubility of nitrogen gas at 50 ?C is 14.6 mg/L at a nitrogen pressure of 1.00 atm. Assume that the air above the water contains an oxygen partial pressure of 0.21 atm and a nitrogen partial pressure of 0.78 atm.
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Exploiting Shale gas in the Karoo: Good or Bad? In your opinion, should South Africa exploit the shale gas reserves in the Karoo. Consider the environmental impacts vs the economic benefits of such an exploitation. (Write no more than 250 words).
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Read about the Flixborough disaster that occurred in 1974 ( or watch a video about it on youtube). What was the cause of the accident and what safety lessons are to be learnt from this disaster? (Write no more than 250 words).
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Solid calcium fluoride (CaF2) reacts with sulfuric acid (H2SO4) to form solid calcium sulfate (Ca... Solid calcium fluoride (CaF2) reacts with sulfuric acid (H2SO4) to form solid calcium sulfate (CaSO4) and gaseous hydrogen fluoride (HF). The HF is then dissolved in water to form hydrofluoric acid. A source of calcium fluoride is fluorite ore containing 96.0 wt% CaF2 and 4.0 wt% SiO2. In a typical hydrofluoric acid manufacturing process, fluorite ore is reacted with 93 wt% aqueous sulfuric acid, supplied 15% in excess of the stoichiometric amount. 95% of the ore dissolves in the acid. The HF(g) exiting the reactor is subsequently dissolved in enough water to produce 60.0 wt% HF (aq). Calculate the product composition from the reactor, and also the amount of water required to generate a 60.0 wt% HF solution.
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advantages and disadvantages of a fixed and fluidized bed adsorbent
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2.00-mol of a monatomic ideal gas goes from State A to State D via the path A?B?C?D:
| State A PA=10.0atm, VA=12.50L |
| State B PB=10.0atm, VB=7.00L |
| State C PC=22.5atm, VC=7.00L |
| State D PD=22.5atm, VD=21.50L |
Assume that the external pressure is constant during each step and equals the final pressure of the gas for that step.
Calculate q for this process.
Calculate w for this process.
Calculate ?E for this process
Calculate ?H for this process.
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Discuss the reasons for introducing nanomaterials to
make better sport equipment.
please answer with specific examples at least 2.
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Nature always gives the valuable inspiration to improve
engineering and science.
List at least 3 examples where we can learn nanoscience and
technology.
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A gas which obeys the equation of state, PV/RT=1 +BP ,
where B is a known
temperature-dependent parameter, is fed at a steady rate to an
insulated valve where its pressure is reduced from P1 to P2. Given
that the upstream temperature of the gas is T1 and that the
constant-pressure molar heat capacity of the gas in the ideal gas
state is given by Cp* = a + bT, where a and b are known constants,
derive an expression for the temperature T2 of the gas downstream
from the valve. Express your answer in terms of the parameters
given above. Neglect the effect of any kinetic energy change across
the valve.
(Chemical engineering)
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