Concept explainers
Interpretation:To explain the concept to choose a better lubricant having high viscosity.
Concept introduction:
Viscosity: It is a common experience of daily
life that different liquids flow with different speeds, for example, water flows in greater speed than glycerol. Obviously some sort of internal friction is operating which checks the flow of liquids and which varies from liquid to liquid. This internal friction in liquids is primarily due to intermolecular force of attraction between the molecules. If we have a laminar flow of liquid in a tube, then the velocity of the layer just in touch with the side of the tube is zero and it increases as we proceed towards the center of the tube as shown in the figure. Thus, there exists velocity gradient between the different layers of the liquids.
Due to greater intermolecular attraction between the molecules of liquids, the molecules moving in any layer will tend to impede the movement of the molecules in the adjacent faster moving layer as a result the velocity of the molecules in the faster layer decreases. Unless this decrease is prevented by applying a force along the layer in the forward direction, the velocity of the faster moving layer will go on decreasing and ultimately it will become zero. At this stage the liquid will stop flowing.
- Lubricant: A lubricant is an organic substance having high molecular weight, which is needed to reduce the interactions between surfaces of two material and control the generation of heat due to the movement of the surfaces. The molecule must have high viscosity for the effective application. It has a wide application in field of motors in vehicle, pump and many a field.
Want to see the full answer?
Check out a sample textbook solutionChapter 8 Solutions
Chemistry for Engineering Students
- Explain the decomposition of nitroglycerin in terms of relative bond enthalpies.arrow_forwardExplain how bond energies can be used to estimate E for a reaction. Why is this an estimate of E? How do the product bond strengths compare to the reactant bond strengths for a reaction that releases energy? A reaction that gains energy? What is the relationship between the number of bonds between two atoms and bond strength? Bond length?arrow_forwardWhich one of the following ionic compounds has the smallest lattice formation enthalpy (lattice energy) thus making it the least favorable to form a stable lattice? A) MgF₂ B) Na₂O C) CaO D) LiBrarrow_forward
- On the basis of your knowledge of bonding in liquids and solids, which of the following has the lowest melting temperature? NaCl, Na, Cl2, SiO2arrow_forwardConsider the compound xenon dichloride, XeCl2 a.What is the polarity of the molecule? b. What type of bond is the Xe-Cl bond? c. How many bonding pairs of electrons are there?arrow_forwardThe precious gem ruby is aluminum oxide, Al2O3, containing traces of Cr3+. The compound Al2Se3 is used in the fabrication of some semiconductor devices. Which has the larger lattice energy, Al2O3 or Al2Se3?arrow_forward
- (a) Based on the lattice energies of MgCl2 and SrCl2 given inTable 8.1, what is the range of values that you would expectfor the lattice energy of CaCl2? (b) Using data from AppendixC, Figure 7.11, Figure 7.13, and the value of the secondionization energy for Ca, 1145 kJ>mol, calculate the latticeenergy of CaCl2.arrow_forwardThe reaction of Fe2O3(s) with Al(s) to form Al2O3(s) and Fe(s) is called the thermite reaction and is highly exothermic. What role does lattice energy play in the exothermicity of the reaction?arrow_forwardWhich has higher lattice energy, AlF3 or AlNarrow_forward
- Which species listed below has the largest lattice energy? A. CaCl2 B. LiCl C. BeO D. CaO E. CaSarrow_forwardThis thermodynamic cycle describes the formation of an ionic compound MX2 from a metal element M and nonmetal element X in their standard states. Based of the table (picture): A. What is the lattice enthalpy of MX2 ? (in kJ/mol) B. What is the enthalpy of formation of MX2 ? (in kJ/mol) C. Suppose both the electron affinity of X and the heat of sublimation of M were smaller. Would MX2 be more or less stable?arrow_forwardThis thermodynamic cycle describes the formation of an ionic compound MX from a metal element M and nonmetal element X in their standard states. Based of the table (picture): A. What is the lattice enthalpy of MX2? (in kJ/mol) B. What is the enthalpy of formation of MX2? (in kJ/mol) C. Suppose the electron affinity of X were bigger and the heat of sublimation of M were smaller. Would MX2 be more or less stable? Or would it be impossible to tell without more information?arrow_forward
- Chemistry for Engineering StudentsChemistryISBN:9781337398909Author:Lawrence S. Brown, Tom HolmePublisher:Cengage LearningGeneral Chemistry - Standalone book (MindTap Cour...ChemistryISBN:9781305580343Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; DarrellPublisher:Cengage LearningChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage Learning
- Chemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage Learning