A liquid is contained in a reactor vessel at 115 bar absolute pressure. It is transferred to a storage vessel through a 50 mm internal diameter commercial steel pipe. The storage vessel is nitrogen blanketed, and pressure above the liquid surface is kept constant at 1500 N/m2 gauge. The total run of pipe between the two vessels is 200 m. The miscellaneous losses due to entry and exit losses, fittings, valves, etc., amount to 800 equivalent pipe diameters. The liquid level in the storage vessel is at an elevation 20 m below the level in the reactor. A turbine is fitted in the pipeline to recover the excess energy that is available, over that required to transfer the liquid from one vessel to the other. Estimate the power that can be taken from the turbine, when the liquid transfer rate is 5000 kg/h. Take the efficiency of the turbine as 70%. The properties of the fluid are density 895 kg=m3 , viscosity 0:76 mNm2s.
In: Chemistry
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1) A piece of bread is inserted into a toaster and begins to toast. Identify the correct statement. |
a The internal energy of the toaster decreases as the internal energy of the bread increases
b Heat enters the bread and the internal energy of the toaster decreases
c Work is done to the bread and the internal energy of the toaster decreases
d Work is done to the bread and heat enters the bread
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2) If a system is doing work on its surroundings, and gaining heat from its surroundings, then which of the following shows the correct signs for heat and work representing the system? |
a q=–,w=+
b q=+,w=–
c q=+,w=+
d q=–,w=–
3. What is the difference between heat capacity (CV) and specific heat capacity (c)?
a CV refers to isochoric conditions, whereas c does not refer to isochoric conditions
b c considers the whole system, whereas CV considers only a unit mass of the system
c CV considers the whole system, whereas c considers only a unit mass of the system
In: Chemistry
A 1 liter sample of a lake water has an Alk of .2 meq/liter and contains .18 mM of carbonate species.
a. what is the pH ?
b. how much does pH change when 5 x 10 to the -5 power mol of hydrochloric acid are added ?
In: Chemistry
* Calculate the concentration of argon in the Pacific Ocean given that the partial pressure of argon is 0.00934 atm. The Henry’s law constant for argon in water at 25ºC is 1.4 x 10-3 mol/L·atm.
* The solubility of potassium chloride (KCl) is 34.2 g per 100.0 g of water at 20ºC.
Calculate the molality of a saturated solution of potassium chloride.
Is a 4.00 m solution of potassium chloride in water at 20ºC saturated, supersaturated, or unsaturated?
Answer: saturated, supersaturated, or unsaturated
Is a 6.00 m solution of potassium chloride in water at 20ºC saturated, supersaturated, or unsaturated?
Answer: saturated, supersaturated, or unsaturated
* A supermarket brand bleach contains 4.88 g of sodium hypochlorite (NaOCl) in 100.0 g of water. Calculate the molality, mass percent, ppm, and mole fraction of sodium hypochlorite in this solution.
Molality of sodium hypochlorite in water
Mass percent of sodium hypochlorite in water
ppm of sodium hypochlorite in water
Mole fraction of sodium hypochlorite in water
In: Chemistry
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Mass of filter paper+ PbI2 |
3g |
| Mass of filter paper | 0.52g |
| Mass of PbI2 | 2.48g |
| Mass(g) Pb(NO3)2 | Mass(g) KI | Mass(g) PbI2 | Moles Pb(NO3)2 | Moles KI | Moles PbI2 |
| 1.66g | 2g | 2.48g | 5x10-3 | 0.012 | 6x10-3 |
The above are the data.
a) using the equation for the reaction ( Pb(NO3)2+2KI --> PbI2 + 2KNO3 ), calculate how much solid PbI2 you should have made. This called theoretical Yield.
b) compare your actual results ( the mass of PbI2 you made) with the theoretical yield ( the mass of PbI2 you should have made). Calculate % yield.
In: Chemistry
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Indicate the oxidation number of each element in the following species. Click in the answer box to open the symbol palette. (a) Cr(s) (b) Br2(l) (c) Cr3+(aq) (d) Br-(aq) |
In: Chemistry
Using clear drawings, give a coordination chemistry example of:
a) ionization isomers
b) fac and mer isomers
c) optical isomers
d) linkage isomers
e) hydrate isomers
In: Chemistry
If you started with 0.274g of benzil and 0.198g of dibenzyl ketone:
1) What is the limiting reagent? How do we find out which one is limiting reagent?
2) What is the theoretical yield of tetraphenylcyclopentadienone? Please show detailed caclulations.
Thank You!
In: Chemistry
a hydrogen-oxygen fuel cell is used in the space program to generate clean energy. Describe, in detail, the principle and process of electrical energy generation from hydrogen-oxygen fuel cell. Also include in the discussion major advantages and limitations of such fuel cells.
In: Chemistry
A 25.0 mL sample of 0.35 M lactic acid, HC3H5O3, is titrated with 0.070 M KOH. Determine the pH of the solution at the equivalence point and at half-way to equivalence point. The Ka of lactic acid is 1.38x10^-4.
In: Chemistry
EX3
A solution contains 2.2x10-3M in CU2+ and 0.33M in LiCN. If the Kf for Cu(CN)42-- is 1.0x1025, how much copper ion remains at equilibrium?
In: Chemistry
Critique the accuracy of each of these statements.
A) Indicators such as methyl red provide accurate and precise measurements of pH.
B) According to the Arrhenius definition of acids and bases, ammonia qualifies as a base.
C) The strength of an acid or base changes as its concentration changes.
In: Chemistry
For the balanced equation shown below, if 98.0 grams of C2H3Br3 were reacted with 62.2 grams of O2, how many grams of Br2 would be produced? 4C2H3Br3+11O2=8CO2+6H2P+6Br2
In: Chemistry
87
What is the change in enthalpy (in kJ) under standard conditions when 246.4 g of sodium sulfate dissolves in water?
Answer:
In: Chemistry
A 1.250 g sample of barium chloride hydrate, BaCl2.xH2O, was
heated until all the water had been driven off. The remaining
anhydrous salt weighed 1.060g. Use this data to calculate the value
of x, the number of moles of water of crystallization in the
hydrated salt. You MUST Show ALL your work for full credit!
5. 0.0185 mol of hydrated magnesium sulfate MgSO4.xH2O has a mass
of 4.56g. Calculate the value of x, the number of moles of water of
crystallization in the hydrated salt. You MUST Show ALL your work
for full credit!
In: Chemistry