Experiment of viscosity - show results and calculations

I need help to solve this experiment

Dhjective: Determine the surface tension of a test liquid by the capillary-rise method. Discussion The surface tension is a measure of the inward pull, or contraction, of the surface molecules resulting from the unbalanced forces at the surface. Surface tensions are measured using capillary-rise method by comparing the rise of the test liquid to the rise of pure water, using Equation 4.1. Figure 4.1 Experimental schematic Equation 4.1 rhpg T = - 2 Where: T = surface tension, dyne/cm p = the density of the liquid, g/ml h = the height of the column, cm " = internal tube radius, cm g = the acceleration due to gravity, 980 cm/s Equipment and Materials Hampden MODEL H-6535 Hydrostatics Bench - Capillary tubes of sizes as follows: . ID of 0.6 mm, 1.2 mm, 2.2 mm, 2.7 mm, and 3.0 mm. Test tube Beaker 1000 ml Clamps and clamp holder Rubber stopper (1 hole) Ruler 150 mm Procedure Step 1. To calculate the surface tension by the capillary-rise method, per Equation 4.1, the density of the fluid must be known. Use Table 1 of Appendix A for standard known liquid densities, or perform Experiment No. 2 to determine the density of the test liquid by either the hydrometer method or the inverted U-Tube method. The Kg/m' is converted to grams/ml by multiplying Kg/m by 10-3. Density of test fluid gms/ml Step 2. Assemble the apparatus, per Figure 4.1. Fill the test tube with pure water, first, to check standardization of the apparatus. Use capillary tube with OD of 5 mm and ID of 0.6 mm. Step 3. Calculate the theoretical height in cm, using Equation 4.1, for pure water for the density given in Appendix A, Table 1 (converted to grams/ml), and the surface tension given in Appendix A, Table 2. Record in Table 4.1 for the size tubes given. Step 4. Connect hose to vacuum port of air pump, as shown in Figure 1-2. Step 5. Close V10, V12 and V13. Open V11 and V14.Vacuum Pressure Port Port Safety Cap (removable) Trigger Vacuum Pump Release Hand Figure 4.2 Vacuum air pump Step 6. Apply gentle suction to raise the water level to the top of the capillary tube. Open V13 and allow the level to fall to equilibrium. Measure height h of the column, as shown in Figure 4.1. Repeat, if necessary, to obtain reliable data. Record height in Table 4.1 and check that it is within 5% of the theoretical height. Step 7. Using a clean test tube and capillary tube, repeat Steps 5 and 6 with test liquid and record the height in Table 4.1. Step 8. Calculate surface tension T in dynes/cm, using Equation 4.1 and Record in Table 4.1. Step 9. Repeat Steps 2 through 8 for the list capillary tube sizes Table 4.1 Tube Size OD by ID Theoretical Height Measured Height Measured Height T Test Fluid (mm H20 (cm) H20 (cm) Test Fluid (cm) (Dynes/cm) 5 x 0.6 6 x 1.2 7 x 2.2 6 x 27 7 x 3.0Observations Conclusions Questions: Compare the theoretical height with the measure height of water. Are they the same? If no, explain, why?. Determine the percent error. For water as test fluid, compare your experimental values of surface tension with the theoretical value. Determine the percent error. How you can minimize the experimental errors. LIQUID SURFACE TENSION (dyne/cm) Alcohol (ethyl) 22.33 Benzene 28.89 Carbon Tetrachloride 26.70 Water 72.67 Mercury 513.68 Table 2 Surface Tension of Common Liquids in Contact with Air at 68 FTable 4.1: Measurement of surface tension Liquid: Water Values: Density: 1 g/ml Tube size OD by ID Radius Height of water-h - (cm) Surface tension-T - (dynas/cm) Gravity: 980 cm/s2 (mm) (cm) Theoretical Measured % Error Theoretical Calculated % Error 5 x 0.6 5.00 6 x 1.2 2.50 6 x 2.7 0.90 7 x 3.0 0.80