Viscosity of Liquids Lap Report
Experiment 1: Viscosity of Liquids
Victoria Kulczak
Lab Partners: Laina Maines & Heidi Osterman
Date of Lab: 2/21/11
Due Date: 2/28/11
Abstract: The goal of this experiment was to determine the viscosity of given liquids. Two different methods were employed, the first measures time of flow of several methanol-water solutions, from point A to point B. The second method involves dropping a foreign object, in this case a sphere, into a cylinder of glycerol and measuring the time it takes for it to travel a specific distance down the tube. The viscosity of a 0%, 20%, 40%, 60%, 80% and 100% methanol by volume solutions was measured to be 0.89, 1.28, 1.53, 1.46, 1.11 and 0.54±0.001P, respectively. The falling sphere method was performed under two different temperatures. At 5.7°C the viscosity of glycerol was calculated to be 29.8±0.1P and at 22.7°C it was 6.3±0.1P.
Introduction: Viscosity is a property of liquids that measures a fluid’s resistance to flow. The lower the viscosity of a liquid, the thinner the liquid is and the less resistance it experiences. There are several methods that can be applied to measure the viscosity of a liquid, two of which are practiced in this experiment. The first part of the experiment uses an Ostwald viscometer to determine how long it takes a liquid to flow through the capillary tube of the viscometer. Poiseuille’s law demonstrates that the laminar flow of a liquid through a small tube is proportional to the fourth power of the tube’s radius, which is employed in the first method. Poiseuille’s law is given in equation 1, in which dV/dt is the volume flow rate, r is the radius, L is length of the tube, ΔP is the pressure difference across the ends of the tube and η is the viscosity.
[pic] (1)
After integrating and rearranging equation 1, a simpler equation is obtained for viscosity which is given by equation 2, in which t is the length of time for a liquid of volume
Victoria Kulczak
Lab Partners: Laina Maines & Heidi Osterman
Date of Lab: 2/21/11
Due Date: 2/28/11
Abstract: The goal of this experiment was to determine the viscosity of given liquids. Two different methods were employed, the first measures time of flow of several methanol-water solutions, from point A to point B. The second method involves dropping a foreign object, in this case a sphere, into a cylinder of glycerol and measuring the time it takes for it to travel a specific distance down the tube. The viscosity of a 0%, 20%, 40%, 60%, 80% and 100% methanol by volume solutions was measured to be 0.89, 1.28, 1.53, 1.46, 1.11 and 0.54±0.001P, respectively. The falling sphere method was performed under two different temperatures. At 5.7°C the viscosity of glycerol was calculated to be 29.8±0.1P and at 22.7°C it was 6.3±0.1P.
Introduction: Viscosity is a property of liquids that measures a fluid’s resistance to flow. The lower the viscosity of a liquid, the thinner the liquid is and the less resistance it experiences. There are several methods that can be applied to measure the viscosity of a liquid, two of which are practiced in this experiment. The first part of the experiment uses an Ostwald viscometer to determine how long it takes a liquid to flow through the capillary tube of the viscometer. Poiseuille’s law demonstrates that the laminar flow of a liquid through a small tube is proportional to the fourth power of the tube’s radius, which is employed in the first method. Poiseuille’s law is given in equation 1, in which dV/dt is the volume flow rate, r is the radius, L is length of the tube, ΔP is the pressure difference across the ends of the tube and η is the viscosity.
[pic] (1)
After integrating and rearranging equation 1, a simpler equation is obtained for viscosity which is given by equation 2, in which t is the length of time for a liquid of volume