Archimedes’ method Object Mass (g) Mass of Displaced Water (g) Volume of Displaced Water (mL) Density (g/mL) Metal Bolt 42.5 25 25 25 Magnet 16.2 3.5 3.5 3.5 Questions: An unknown, rectangular substance measures 3.6 cm high, 4.21 cm long, and 1.17 cm wide. If the mass is 21.3 g, what is this substance’s density (in grams per milliliter)? 1.2 g/ml A sample of gold (Au) has a mass of 26.15 g. Given that the theoretical density is 19.30 g/mL, what is the volume of the gold sample? 1.35 mL What would happen if you dropped the object into the beaker while using the Archimedes’ Principle method instead of submerging the object? The measurements would be the same.
Pour all the filtrate and washings into a 250cm3 volumetric flask. Make up to 250cm3 with 1.0mol dm-3 sulphuric acid(VI) acid. Stopper the flask and invert several times to thoroughly mix the solution. 5. Fill the burette with 0.005mol dm-3 potassium manganate(VII) solution.
is 0.0020 g or less. III. Data Mass of crucible, cover, and unknown sample | 29.082 g | Mass of crucible and cover | 23.110 g | 1st Mass of crucible, cover, and residue | 28.403 g | 2nd Mass of crucible, cover, and residue | 28.365 g | Mass of unknown sample used | 5.972 g | Mass of water lost by the sample | .717 g | Calculated mass of BaCl2* 2H2o in unknown sample | 4.86 g | % by weight of BaCl2*2H2O in unknown sample | 81.4 % | % by weight of NaCl in unknown sample | 18.6 % | IV. Calculations V. Post-lab
Calculate the surface area of the circle formed (πd2/4): Surface area = .785 cm2 2. Calculate the number of molecules on the top layer. We must convert the surface area in centimeters squared to nanometers squared and then multiple that by the surface area of a sodium stearate molecule. Convert the surface area of the circle formed (#1) to molecules per layer using the matrix below: Answer = 4.76*10^14 molecules/top layer 3. Calculate the concentration of grams of sodium stearate per milliliter of diluted solution.
Gravimetric Analysis of a Metal Carbonate Post Lab TABLE Mass of Crucible + M2CO3 14.8145g Mass of Crucible + M2CO3 (1st weighing) 14.7915g Mass of Crucible 12.9405g Mass of M2CO3 1.851g Mass of filter paper + CaCO3 3.8025g Mass of filter paper 1.8120g Mass of CaCO3 1.9905g Moles of CaCO3 0.019887 mol Molar mass of M2CO3 93.08 g/mol Identity of M2CO3 Na2CO3 Percent Error 12.18% error ANALYSIS QUESTIONS 1. Calculate the moles of precipitated calcium carbonate, CaCO3. Enter this value in the Data Table. 1.9905g CaCO3 x 1 mol CaCO3 = 0.019887 mol CaCO3 1 100.09g 2. Calculate the molar mass of the unknown carbonate.
Part I: Density of Unknown Liquid | | Trial 1 | Trial 2 | Trial 3 | Mass of Empty 10 mL graduated cylinder (grams) | 25.5g | 25g | 25g | Volume of liquid (milliliters) | 8.6mL | 8.7mL | 8.4mL | Mass of graduated cylinder and liquid (grams) | 36g | 36g | 35.5g | Part II: Density of Irregular-Shaped Solid | Mass of solid (grams) | 38.74g | 39.002g | 42.489g | Volume of water (milliliters) | 50mL | 49mL | 51mL | Volume of water and solid (milliliters) | 54mL | 53mL | 56mL | Part III: Density of Regular-Shaped Solid | Mass of solid (grams) | 26g | 27g | 26g | Length of solid (centimeters) | 5.2cm | 5cm | 4.5cm | Width of solid (centimeters) | 3cm | 4cm | 3.5cm | Height of solid (centimeters) | 2.5cm | 3cm | 2cm | Calculations Show all of your work for each of the following calculations and be careful to follow significant figure rules in each calculation. Part I: Density of Unknown Liquid 1. Calculate the mass of the liquid for each trial. (Subtract the mass of the empty graduated cylinder from the mass of the graduated cylinder with liquid.) * Trial 1 36-25.5=10g * Trial 2 36-25=11g * Trial 3 35.5-25=10g 2.
Which one is not a pure substance? A) water B) oxygen C) air D) chlorine 6. Passing an electric current through a certain substance produces oxygen and sulfur. This substance cannot be a(n) A) compound B) mixture C) element D) pure substance 7. The symbol for the element potassium is A) K B) Kr C) P D) Pt E) Po 8.
Weigh the calorimeter empty. 2. Reweigh the calorimeter when it is about half full of water. 3. The temperature of the water is read and recorded.
APPARATUS: Burette (50 cmᶾ), Pipette (25 cmᶾ), two conical flasks (250 cmᶾ), two beakers (250 cmᶾ), funnel, wash bottle, retort stand, boss and clamp, evaporating dish, pipette filler, hot-plate. MATERIALS: Approximately 2.0 mol dmˉ³ hydrochloric acid, 1.0 mol dmˉ³ sodium hydroxide, methyl orange indicator. METHOD: 1. Firstly, the burette was rinsed with a little hydrochloric acid and filled up to just above the zero mark. 2.
(3 marks) (ii) What is the chromatographic mechanism involved? Describe how the mechanism effects separation to the three compounds. (8 marks) (iii) With explanation, describe what would happen to the peaks in the chromatogram when the packing silica with a larger pore size and smaller surface area is used in the above separation. (6 marks) 2. A mixture of Br-, Cl- and PO43- ions was subjected to an anionic column packed with polym-N(CH3)3+OH-, eluted with 9mM sodium carbonate.