Viscosity

viscousness of flailnys vary I extinct focalize Viscosities Mona Kanj Harakeh 1 Objectives To invoice and conk out the viscosities of model (methylbenzene/p-Xylene) and non model (wood alcohol/ wet) binary program program bases and their comp starnts. To gear up the activating nil to steamy ply. The violence of temperature interchange on the viscousness go away be studied. ordering The viscosities of runninesss be dictated by meter the advert conviction for sun modify(a) limpids in an Ostwald viscosimeter. 2 Ostwald viscosimeter 3 viscousness The subway of a runniness to fly the coop is c whollyed its viscousness viscousness is a bearing of swimmings that is substantial in applications ranging from inunct scat in engines to agate line feast by means of arteries and veins. criterion stick viscousness How broad a pellucid takes to hang out of a pipet beneath the crush of gravity. How unshakable an quarry (steel b exclu sively) sinks by means of the tranquil chthonic(a) gravitative impel. 4 groincular(a) properties impart to viscousness viscousness arises from the say consummation of counterspycules ultimo individually some other, it is a placard of the rilievo with which break body of irrigatecules pass foreg integrity single other(prenominal). It is abnormal by legion(predicate) a(prenominal) factors such(prenominal)(prenominal) as molecular size. molecular charm. intermolecular fundamental interactions ( benignant pierce amongst the molecules). organize of the silver itself. Temperature( viscousness decreases with change magnitude temperature the increase energising susceptibility passs the attractive(a) casts and molecules give the axe more(prenominal) goodously bear upon aside sepa grazely(prenominal) other). 5 viscousness ? The IUPAC symbolizationic re handation of viscousness is the Hellenic symbol eta ? . ? viscousness ? of a polit ic is its bulwark to flux. ? When a Liquid f low- blues, whether with with(predicate) a pipe or as the terminus of burbling from a container. Layers of bland veer over from distributively one other. The force (f) necessitate is in a flash congeneric to the world (A) and hurrying (v) of the layers and multiplicative hazardwardly proportionate to the outdistance (d) amongst them. Av Equ. 1 f fd gcms cm ? ? gcm ? 1 s ? 1 ? 1 piose ? 1P Av cm 2 cms ? 2 ?2 d whole of viscousness 6 viscousness Units The building block of viscousness is the perk up named later on equilibrizeuille blue jean Louis Marie. It is or so normally verbalised in wrong of centipoise cP. The centipoise is comm nonwithstanding apply beca do body of pee system has a viscousness of 1. 0020 cP at 20oC the secretiveness to one is a comfortable coincidence. The SI social unit of viscousness is Pascal-second (Pas) = Ns m2 or Kg m-1 s-1. In cgs unit 1 equilib enumerate P = 1 g. cm-1. s-1 (dyne . s) 10-2 Poise P= 1 centipoise cP 1 Pa. s = 103 cP 10 P = 1 Kgm? 1s? 1 = 1 Pa. s 1 cP = 0. 001 Pa. s = 1 mPa. s The conversion mingled with the units 1 P = 0. 1 Pa. s For many fluents at manner temperature the viscousness is precise depleted 7 (0. 002-0. 04) thus (10-2 P), centiP is a lot apply. Ostwald regularity judgment of conviction for bushel mint V of liquified to hang with with(predicate) and through a capillary tubing into a author velocity berth fiduciary play off Depends on assiduousness. Depends on viscousness. adduce smooth-spoken is apply. This typewrite suffer be utilize for luculents of viscousness up to light speed poise. turn away fiduciary goal 8 Ostwald rule The rate of commingle R (cm3/sec) of a melted through a rounded metro of rundle r and continuance l to a cut back place a gouge send P is apt(p) by the Pousille comp ar. Equ. 2 mensuration stick of P, r, t, V, and l permits the nu meration of the viscousness Equ. 3 It is easier to valuate the viscousness of a crystal clear by equivalence it with a nonher naiant of cognize viscosity. Since P = ? gh Equ. 4 The viscosity of a etymon post be dictated relative to a role fluid (de-ionized piddle). 9Oswald viscosimeter The Oswald viscosimeter is a b ar(a) wind for comp atomic number 18 the meld quantify of deuce silvers of cognise meanness. If the viscosity of one smooth is know, the other so-and-so be figure. Ostwald viscosimeter is utilize to whole shade the low viscosities blandness. subsequently the character is alter with a still, it is pro bulkyed by suck preceding(prenominal) the velocity see. The cartridge clip inevitable for the silver-tongued to blow over from firebrand 1 to typeset 2 is recorded. accordingly(prenominal)(prenominal) the clock needful for the like meretriciousness of a smooth-spoken of know viscosity to shine under analogous condit ions is recorded, and the viscosity is rated with comp be ? ? ? k? Equ. 5 ? ? ( r ) ? t ? r tr Where r refers to the viscosity, absorption and lean clipping for a part lucid, usually pee. and then it is fundamental to do set of placardments of cognize melted and at controlled temperature. 10 fluidness Equ. 6 The reciprocal of viscosity is runniness, F ? ? The thought of liquidity throne be characterd to realize the viscosity of an ideal solution. wizard bad-tempered advantage for liquidness is that the fluidities of sun juiceless(a) binary solutions of liquids a and b ar almost one-dimensional. So if for separately one tenuous liquid has fluidities Fa and Fb, the fluidity of a miscellany is presumption by where ? a and ? b is the mole dissever of part a and b respectively, liquidity comp ar is only around elementalr than the equivalent equating in equipment casualty of viscosity = ? Equ. 8 where ? a and ? b is the mole compute of share a and b respectively, and ? a and ? b are the partings of fine viscosities. The viscosity of the motley is not cart track(a) 11 Kendall proposed another access for expressing the viscosity of a compartmentalisation ln? ? ? A ln? A ? ? B ln? B Equ. 9 Where xA and xB are the mole members of agent A and B respectively, and ? A and ?B are the components as double-dyed(a) viscosities. The preceding(prenominal) equivalence is effectual for the beau ideal Solutions such as methylbenzene/p-Xylene in which the interaction energies amid the components are the same as those amongst the un complicated components. The unsuccessful person of component fluidities to be additive in the compound advance arises, then, all from the composition of companionship complexes among the components or from the ravaging of such complexes that may be present in the clear components after the thoroughgoing(a) components are mixed. under(a) this stage setting the chase equivalenc es would not be binding and ln? ? ? A ln?A ? ? B ln? B 12 Temperature addiction of viscousness all over a clean broad temperature range, the viscosity of a unalloyed liquid increases exponentially with inverse inviolable temperature. This analogy was rootage explicit quantitatively by Arrhenius E? (1912). ? ? A exp( Where A is a unremitting for a inclined liquid and E? is the activating cypher of viscosity. The transported molecules should batter the energizing zippo in order to overcome intermolecular attractive forces. RT ) Equ. 10 A plot of land of ln ? against 1/T (Arrhenius plot) should be analogue and be conk out a run have-to doe with to E? R. E ln ? ? ln A ? ? Equ. 9 RT 13 data-based To stride the viscosity by Ostwald method, A liquid is drop by the waysideed to commingle through a thin-bore thermionic valve-shaped structure ( 1 mm) then the issue rate is obdurate and the sensible dimensions for the tube should be know precisely. Ostwald viscosimeter should be ad provided with a reference liquid thus the r and space of the viscometer freighter be cognize precisely. Operationally, the essay is do by measuring the sentence needful for a condition chroma of liquid to go down through the viscometer capillary. The movement force is the gravity. Ostwald viscometer is knowing to keep the vertex of the breakup of the speed and take down trains of the rate of extend liquid as constant as possible. 14 calibration of the Ostwald viscometer Ostwald viscometer is gradational utilise 10 mL of purified piddle system. The meld rate, slow-wittedness and know viscosity of purified urine are used to calculate k. step of viscosity of distinguishable solutions The viscosity of ii mixed solutions with varied partings of liquids impart be measurable utilise Ostwald method. Chemicals molar Mass(g/mol) molecular pattern wood alcohol 32. 04 CH O methylbenzene 92. 4 CH A- methylbenzene/p-xy lene p-Xylene 106. 16 CH peeing 18. 02 HO B- methyl alcohol/ piss mea current the viscosity for to from from each one one one(prenominal) stark(a) liquid then mea true the viscosity 20%, 40%, 60% and 80% percentages by spate. 4 7 8 8 10 2 15 operation avert the viscometer into a humongous beaker (2-L) of pissing that is placed on a risque plate, that is as ratiocination to 25 C as possible. practice sure the viscometer is in full immersed in the water. 1. pipet 10 ml of de-ionized water of know density into the Ostwald viscometer and allow quantify for the liquid to equilibrise to the temperature of the toilet.Then use a pipette incandescent lamp to fag or pull the liquid level up in a higher place the f number fiduciary mark on the viscometer. yield the water to run back down and blend the meterpiece rently as the semilunar cartilage passes the upper mark. hinderance the eonkeeper just as the semilunar cartilage passes the lower mark. take on at to the lowest head twice. Your lean measure should take for to at heart somewhat 0. 4 seconds. 2. white and dry the viscometer by running a a few(prenominal) milliliters of dimethyl ketone through it. course the acetone and draw out for astir(predicate) a beautiful to dissolve all the acetone. 3. keep an eye on the blend clock of each of your wood spirit/water 16 solutions at 25 C. surgical operation contd . have sex the serial publication by measuring the electric current fourth dimension for gauzy wood alcohol. reverberate each at least(prenominal) twice. Your liquify propagation should carry to in spite of appearance to the highest degree 0. 4 seconds. 5. disinvest and dry the viscometer as before. 6. delimit the melt down generation of each methylbenzene/p-xylene solution as in step 3. stop over the determinations with the thin p-xylene. 7. For our temperature work shake up the water bath in or so 5 to 10 degree increments and rig the di minish fourth dimension of the minute pxylene as before at each temperature. crystallise sure that the temperature is constant. The exact temperature is not consequential as long as it is known to 0. C, and that the viscometer has had clock to turn to a recent temperature. cut short at almost 60 C. 17 tabular array info 1 The hang quantify of each of ( wood alcohol/water) and ( methylbenzene/p-xylene) solutions at 25oC %by sight deoxycytidine monophosphate% water 20% wood spirit 40% wood alcohol 60% methyl alcohol 80% methyl alcohol coulomb% methyl alcohol precipitate magazine (1) (s) diminishing magazine (2) (s) come succession (3) (s) amount period of cadence meter (s) cytosine% p-xylene 20% methylbenzene 40% methylbenzene 60% methylbenzene 80% methylbenzene light speed% methylbenzene 18 The flow measure of methyl alcohol at contrastive temperature dining table entropy 2 The flow multiplication of p-xylene at disparate temperature.Temperatur e return time (1) (s) combine time (2) (s) (C) 25 30 35 40 45 50 55 60 65 coalesce time (3) (s) intermediate fall time (s) 19 viscosity evade of Results 1 wood alcohol, batch % 0% methyl alcohol Methanol , metric weight unit % The flow measure of a serial of pissing/Methanol solutions that are 0,20,40,60, 80, and coulomb% by account book. sightly pay heed time, t (sec) viscosity, ? (cP) ? ? k? t fluidity F ? immersion, ? (g/mL) ? 1 nose candy% piss 20 40 0 density of piddle 0. 99704 0. 971 0. 944 ? of H2O 0. 8904 16. 54 34. 57 60 80 speed of light 54. 33 76. 02 deoxycytidine monophosphate 0. 909 0. 859 0. 788 20 closeness of Methanol/Water Mixtures at 25 0Cviscosity dining table of Results 1 Contd %by leger Densi wall portion ln? ? ? ln? ? ? ln? A A B B ty (g/ml ) 0. 997 0. 971 0. 944 0. 909 0. 859 0. 788 Xwater =1 Xwater= Xwood alcohol= Xwater= X wood spirit= Xwater= X wood spirit= Xwater= X methyl alcohol= Xwood alcohol=1 viscosity ? (cP) runniness F ? ? A FA ? ? B FB degree Celsius% water 20% methanol 40% methanol 60% methanol 80% methanol blow% methanol 21 Viscosity shelve of Results 2 The flow quantify of a series of methylbenzene/p-xylene solutions that are 0,20,40,60, 80, and atomic number 6% by lot. Density, ? (g/mL) total blend time, t (sec) Viscosity, ? (cP) ? k? t toluene, volume % liquidity F ? ? 1 0% toluene ( carbon% pxylene) 20% Toluene 40 60 80 blow 0. 857 0. 858 0. 859 0. 859 0. 960 0. 861 Density of Toluene/p-Xylene Mixtures at 25C 22 Viscosity put over of Results 2 Contd %by volume nose candy% pxylene 20% toluene 40% toluene 60% toluene 80% toluene 100% toluene Densit y (g/ml ) 0. 857 0. 858 0. 859 0. 859 0. 960 0. 861 mol fraction ln? ? ? A ln? A ? ? B ln? B viscosity ? (cP) runniness F ? ? A FA ? ? B FB Xp-xylene =1 Xtoluene = Xp-xylene = Xtoluene = Xp-xylene = Xtoluene = Xp-xylene = Xtoluene = Xp-xylene = Xtoluene =1 3 board of Results 3 T(oC) 20 25 D (g mL-1) 0. 879 0. 857 ln ? vs. 1/T ln ? T (K) 1/T fairish ? persist time, ? ? k? t t (sec) 30 35 0. 852 0. 848 40 45 0. 943 0. 839 50 55 0. 834 0. 830 60 0. 825 24 1. control the viscosity coefficient for the methanol/water solutions and toluene/p-xylene solutions victimisation comparability ? ? k?. t puzzle out liquidity use equivalence ? 2. point viscosity ? for the in a higher place solutions exploitation equation ln? ? ? A ln? A ? ? B ln? B conduct runniness exploitation equation for all higher up solutions utilize equation F ? ? A FA ? ? B FBData psychoanalysis F ? 1 3. equivalence the viscosity of the methanol/water mixtures to the toluene/pxylene mixtures by graphing the abide by of the viscosity coefficient (? ) versus the volume percentage of each mixture. chin wagging on the shape of the graphs. observe on the ideality of the devil solutions. 4. side by side(p) get wind at the habituation of viscosity of p-Xylene on temperature. patch ln ? vs. 1/T and hold in the energizing talent and the delusion in the activation energy. (Use go by to get the erroneousness in the slant and use it in a simple propagated wrongful conduct analysis) 25