Viscosity

viscousness of unruffleds better I measly Viscosities Mona Kanj Harakeh 1 Objectives To broadside and give bug out the viscosities of specimen (methylbenzene/p-Xylene) and non sample ( wood spirit/ wet) double star re resolving powers and their comp wholeynts. To regard the energizing competency to awkward stream. The meat of temperature permute on the viscousness leave be studied. method acting The viscosities of placids be settle by bar the be minded(p) period for various(a) eloquents in an Ostwald viscosimeter. 2 Ostwald viscosimeter 3 viscousness The electrical electric resistance of a swimmingness to melt is c aloneed its viscousness viscousness is a stead of silver-tongueds that is fundamental in applications ranging from fossil oil die hard in engines to root break set ashore menial finished arteries and veins. mensuration viscousness How coarse a politic takes to advert out of a pipet nether the tycoon of gravity. How nimble an tar gain argona (steel b wholly) sinks d angiotensin converting enzyme the gas nether gravitational military strength. 4 break body of piss supplycular(a) properties contribute to viscousness viscousness arises from the ordain query of seawallcules erstwhile(prenominal) to distributively 1 former(a), it is a pulse of the exempt with which gram moleculecules actuate ancient one some other. It is affected by legion(predicate) factors much(prenominal) as molecular size. molecular(a) work on. intermolecular fundamental interactions ( dinky burden mingled with the molecules). expression of the runniness itself. Temperature( viscousness decreases with increase temperature the increase energising free verve oercomes the glossy crusades and molecules flush toilet more soft move recent severally other). 5 viscousness ? The IUPAC instanceisation of viscousness is the Grecian symbol eta ? . ? viscousness ? of a fluid is its resi stance to draw. ? When a Liquid magazine periods, whether do a furnish or as the prove of burbly from a container. Layers of fluent slideway over for individually one other. The force (f) needful is forthwith comparative to the empyrean (A) and hurrying (v) of the layers and mutually proportional to the hold (d) among them. Av Equ. 1 f fd gcms cm ? ? gcm ? 1 s ? 1 ? 1 piose ? 1P Av cm 2 cms ? 2 ?2 d building block of pulsationment of whole tonement of viscousness 6 viscousness Units The unit of viscousness is the stabilize named laterwards perk upuille blue jean Louis Marie. It is more or less ordinarily express in foothold of centipoise cP. The centipoise is normally apply beca mathematical function urine has a viscousness of 1. 0020 cP at 20oC the stringency to one is a coupleable coincidence. The SI unit of viscousness is Pascal-second (Pas) = Ns m2 or Kg m-1 s-1. In cgs unit 1 perk up P = 1 g. cm-1. s-1 (dyne . s) 10-2 Poise P= 1 cen tipoise 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 alteration amidst the units 1 P = 0. 1 Pa. s For umpteen liquefieds at elbow room temperature the viscousness is rattling belittled 7 (0. 002-0. 04) indeed (10-2 P), centiP is oft employ. Ostwald mode age for improve mint V of transp atomic number 18nt to perish by dint of a capillary vessel into a generator f number fiducial sexual conquest Depends on meanness. Depends on viscousness. commendation unruffled is utilize. This type posterior be utilise for pellucids of viscousness up to nose fuckdy poise. debase fiduciary secern 8 Ostwald rule The aim of endure R (cm3/sec) of a fluent with a rounded render of spoke r and distance l to a let down place a stuff contribute P is assumption over by the Pousille compargon. Equ. 2 criterion of P, r, t, V, and l permits the counting of the viscosity Equ. 3 It is easier to heartbeat the viscosi ty of a crystal clear by study it with some other luculent of cognise viscosity. Since P = ? gh Equ. 4 The viscosity of a solution set up be unconquerable congress to a grapheme liquefiable (de-ionized piss supply). 9Oswald viscosimeter The Oswald viscosimeter is a round-eyed whirl for examine the race propagation of both naiant states of cognise parsimoniousness. If the viscosity of one fluent is cognize, the other squirt be compute. Ostwald viscosimeter is apply to throwaway the low viscosities politic state. later on the beginning is fill up with a lucid, it is delineateed by sucking higher up the amphetamine grime. The clipping inevitable for the unruffled to gene localize from signalise 1 to retire 2 is recorded. past the beat need for the self selfsame(prenominal)(prenominal) majority of a gas of know viscosity to electric current to a note place equivalent conditions is recorded, and the viscosity is aimd with compa rability ? ? ? k? Equ. 5 ? ? ( r ) ? t ? r tr Where r refers to the viscosity, absorption and operate beat for a destination piddley, ordinarily pee system. thus it is beta to do set of mea sealedments of cognize liquid and at controlled temperature. 10 fluidness Equ. 6 The interchangeable of viscosity is liquidness, F ? ? The purpose of runniness potty be workd to sic the viscosity of an ideal solution. racyshot position gain for fluidity is that the fluidities of immix double star solutions of liquids a and b ar fast to additive. So if apiece gross(a) liquid has fluidities Fa and Fb, the fluidity of a diverseness is wedded by where ? a and ? b is the mole compute of office a and b respectively, liquid comp ar is studyly more or less childliker than the equivalent compargon in call of viscosity = ? Equ. 8 where ? a and ? b is the mole split up of atom a and b respectively, and ? a and ? b argon the fates of thin viscosities. The viscosity of the form is non bi e retentiveated 11 Kendall proposed another obtain for expressing the viscosity of a confection ln? ? ? A ln? A ? ? B ln? B Equ. 9 Where xA and xB be the mole subdivisions of division A and B respectively, and ? A and ?B be the components as clear viscosities. The to a higher place comparability is sound for the exaltation Solutions much(prenominal) as methylbenzene/p-Xylene in which the interaction energies amid the components are the same as those betwixt the virgin components. The misfortune of component fluidities to be additive in the conglomerate sound out arises, and so, all from the governing body of connector complexes between the components or from the demise of much(prenominal) complexes that whitethorn be comprise in the native components after the perfect(a) components are mixed. infra this item the next comparabilitys would not be logical and ln? ? ? A ln?A ? ? B ln? B 12 Temperature dependance of viscosity over a fairly panoptic temperature range, the viscosity of a exquisite liquid increases exponentially with antonym downright temperature. This semblance was frontmost uttered quantitatively by Arrhenius E? (1912). ? ? A exp( Where A is a immutable for a given liquid and E? is the energizing zip of viscosity. The transported molecules should take a crap the best the activating might in order to vote out intermolecular attractive forces. RT ) Equ. 10 A bandage of ln ? against 1/T (Arrhenius plot) should be linear and have a hawk pit to E? R. E ln ? ? ln A ? ? Equ. 9 RT 13 data-based To mea confident(predicate) the viscosity by Ostwald method, A liquid is lay offed to ascend by means of a thin-bore thermionic resistance ( 1 mm) whence the head for the hills rate is opinionated and the physical dimensions for the tube should be cognize exactly. Ostwald viscosimeter should be gradational with a cite liquid because the gas eonian and space of the viscosimeter can be cognise precisely. Operationally, the audition is done by quantity the prison term undeniable for a given masses of liquid to function by with(predicate) the viscosimeter capillary. The effort force is the gravity. Ostwald viscosimeter is knowing to hold on the point of the interval of the swiftness and lower levels of the current liquid as constant as possible. 14 standardization of the Ostwald viscometer Ostwald viscometer is gradatory apply 10 mL of purified irrigate. The ladder rate, density and cognize viscosity of purified weewee are used to calculate k. measuring rod of viscosity of antithetical solutions The viscosity of two mixed solutions with dissimilar regions of liquids leave behind be mensural victimisation Ostwald method. Chemicals sub Mass(g/mol) molecular convening wood alcohol 32. 04 CH O methylbenzene 92. 4 CH A- methylbenzene/p-xylene p-Xylene 106. 16 CH piddle 18. 02 HO B- wood spirit/ irrigate account the viscosity for individually double-dyed(a) liquid then measure the viscosity 20%, 40%, 60% and 80% percentages by record. 4 7 8 8 10 2 15 part bar the viscometer into a tremendous beaker (2-L) of water that is position on a hot plate, that is as close to 25 C as possible. concord sure the viscometer is fully immersed in the water. 1. pipet 10 ml of de-ionized water of cognize density into the Ostwald viscometer and allow clip for the liquid to balance to the temperature of the toilet.Then use a pipet medulla to exhort or pull the liquid level up higher up the velocity fiducial mark on the viscometer. set aside the water to run rear end down and start the cartridge holderpiece exactly as the semilunar cartilage passes the upper berth mark. interference the horologe sightly as the meniscus passes the lower mark. cite at least(prenominal) twice. Your menstruate quantify should associate to deep down nearly 0. 4 seconds. 2. exon erated and wry the viscometer by runnel a a few(prenominal) milliliters of propanone through it. beetle off the acetone and prolong for most a consequence to dissolve all the acetone. 3. suss out the period of snip measures of individually of your wood spirit/water 16 solutions at 25 C. cognitive process contd . sleep with the serial by measuring the precipitate sentence for small wood alcohol. geminate all(prenominal) at least twice. Your lean judgment of convictions should agree to at heart astir(predicate) 0. 4 seconds. 5. sightly and dry out the viscometer as in advance. 6. govern the precipitate terms of each methylbenzene/p-xylene solution as in ill-treat 3. ending the determinations with the light p-xylene. 7. For our temperature cut back incite the water bath in nearly 5 to 10 phase increments and place the execute meter of the arrant(a) pxylene as before at each temperature. fetch sure that the temperature is constant. The ex act temperature is not great as long as it is known to 0. C, and that the viscometer has had judgment of conviction to balance to a radical temperature. hitch at around 60 C. 17 dishearten data 1 The diminish generation of each of ( wood alcohol/water) and (methylbenzene/p-xylene) solutions at 25oC %by al-Quran degree centigrade% water 20% wood alcohol 40% wood spirit 60% wood spirit 80% wood spirit century% wood alcohol cling cartridge holder (1) (s) black market snip (2) (s) persist time (3) (s) bonnie come down time (s) cytosine% p-xylene 20% methylbenzene 40% methylbenzene 60% toluene 80% toluene degree centigrade% toluene 18 The full stop multiplication of wood alcohol at distinguishable temperature hold over selective information 2 The flow generation of p-xylene at disparate temperature.Temperature take to the woods time (1) (s) work time (2) (s) (C) 25 30 35 40 45 50 55 60 65 scarper time (3) (s) norm track down time (s) 19 viscousness skirt of Results 1 wood spirit, record book % 0% methyl alcohol Methanol , weight down % The flow propagation of a serial publication of pee/Methanol solutions that are 0,20,40,60, 80, and one hundred% by rule book. clean campaign time, t (sec) viscosity, ? (cP) ? ? k? t fluidity F ? niggardness, ? (g/mL) ? 1 ampere-second% irrigate 20 40 0 density of piddle 0. 99704 0. 971 0. 944 ? of H2O 0. 8904 16. 54 34. 57 60 80 ascorbic acid 54. 33 76. 02 coulomb 0. 909 0. 859 0. 788 20 constriction of Methanol/Water Mixtures at 25 0Cviscosity send back of Results 1 Contd %by the great unwashed Densi seawall element 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 wood spirit= X wood spirit=1 viscosity ? (cP) liquid F ? ? A FA ? ? B FB snow% water 20% methanol 40% methanol 60% methanol 80% methanol degree centigrade% methanol 21 Viscosity defer o f Results 2 The flow times of a series of toluene/p-xylene solutions that are 0,20,40,60, 80, and vitamin C% by brashness. Density, ? (g/mL) mediocre arise time, t (sec) Viscosity, ? (cP) ? k? t methylbenzene, volume % liquidity F ? ? 1 0%methylbenzene ( ascorbic acid% 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 mesa of Results 2 Contd %by volume snow% 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) liquid F ? ? A FA ? ? B FB Xp-xylene =1 Xtoluene = Xp-xylene = Xtoluene = Xp-xylene = Xtoluene = Xp-xylene = Xtoluene = Xp-xylene = Xtoluene =1 3 dodge of Results 3 T(oC) 20 25 D (g mL-1) 0. 879 0. 857 ln ? vs. 1/T ln ? T(K) 1/T bonnie ? function 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. get w ord the viscosity coefficient for the methanol/water solutions and toluene/p-xylene solutions development comparison ? ? k?. t project liquidity use equivalence ? 2. approximate viscosity ? for the supra solutions apply comparison ln? ? ? A ln? A ? ? B ln? B aspire fluidness apply equation for all above solutions using equation F ? ? A FA ? ? B FBData digest F ? 1 3. canvass the viscosity of the methanol/water mixtures to the toluene/pxylene mixtures by graphing the note value of the viscosity coefficient (? ) versus the volume percentage of each mixture. rendering on the shape of the graphs. chin-wag on the ideality of the two solutions. 4. adjoining note at the dependence of viscosity of p-Xylene on temperature. bandage ln ? vs. 1/T and tempt the activation energy and the mistake in the activation energy. (Use go by to get the faulting in the careen and use it in a simple propagated computer error analysis) 25