To do this, first take the number of drops used to achieve the monolayer (1 drop) and convert it to mL using the calibrated number of drops per mL. Then multiply the number of grams of sodium stearate per milliliter of solution. Finally, convert to moles through the molar mass of sodium stearate. HINT: The molar mass of sodium stearate is 296.5 g/mole. Answer = 1.06*10^7 moles/top layer 5.
6. Obtain a plastic foam cup to be used as a calorimeter and measure the mass carefully. Record. 7. Fill the plastic cup about half full with distilled water at room temperature and record the mass.
* 5ml of distilled water was poured down the sides of the beaker, swirled and poured into the funnel. * The filter paper containing the precipitate was allowed to dry and then weighed. 1.7g/1.4g * The weight of the filter paper was subtracted (1.1g/0.7g) to give the actual yield of calcium carbonate (0.6g/0.7g). Observations: * When CaCl2 and Na2CO3 were mixed, a white precipitate was noted immediately. * Residual precipitate was observed on the beaker when filtering.
Lab 4: Determination of Percent by Mass of the Composition in a Mixture by Gravimetric Analysis Introduction Thermal gravimetric analysis is used to determine the percent by mass is used to determine the percent by mass of a component in a mixture. When a mixture is heated to an appropriately high temperature, one component in the mixture decomposes to form a gaseous compound. The mass of this particular component is related to the mass of the gaseous compound. In this experiment, the percent by mass of sodium hydrogen carbonate (NaHCO3) and potassium chloride (KCl) in a mixture will be determined. Experimental First, we weighed 2 samples, each has 1 gram of NaHCO3-KCl mixture Second, we put the samples in 2 crucibles (A and B) and weighed them.
Materials: • 2 Graduated Cylinders • Distilled Water • Stirring Rod • Balance • One 250ml Beaker • One Erlenmeyer Flask • Filter Paper • Copper (II) Sulphate Pentahydrate • Strontium Chloride Hexahydrate Procedure 1. Two graduated cylinders are used and 75ml of distilled water are added to both 2. The two reactants are made into a solution by
Gravimetric Determination of Sulfate Purpose The purpose of this lab is to determine the percentage of sulfate in the hydrate by precipitating the sulfate as barium sulfate. Materials Filler paper Sodium sulfate Graduated cylinder Bunsen burner Watch glass Beakers (250 mL, 400 mL) Rubber bulb Graduated pipette Beaker tongs Funnel Filter Paper Sodium Sulfate Drying oven Wash bottle Stirring rod Silver nitrate Hydrochloric acid Distilled water Small test tube Procedures First, .4861 grams of sodium sulfate was placed into a clean 400mL beaker. Exactly 200mL of water and 1mL of HCl was added to the same beaker. A watch glass was placed on the beaker and the solution was heated using the Bunsen burner to a gentle boil. The watch glass was removed with the beaker tongs.
In each trial, the initial reading, final reading and the volume of HCl used was recorded down as quantitative results. The average volume of hydrochloric acid was found to be 12.03mL. The amount of sodium carbonate in the 10.00ml of solution was found to b 0.05 mol. The amount of hydrogen chloride that was dissolved in the average volume of acid is 0.365g. Through these calculations, the concentration of hydrochloric acid was found to be 8.3 mol•L-1.
Mixture is gently swirled and drained out into an Erlenmeyer flask. Anhydrous magnesium sulfate is added to dehydrate the washed mixture. The solution is then filter into a weighed, dry, 100mL Erlenmeyer flask. Dichloromethane in the mixture is vaporized with a rotary evaporator. The Caffeine, white powder residue, (0.0486g) should be obtained.
The cylinder was weighed empty, and then graduated cylinder was filled to a certain volume according to the graduations on it and weighed again. The difference in weight was divided by the volume gives the weight per unit volume of the fluid. The liquid density was calculated. The mass per unit volume, or the density, was thus measured in a direct way. [5] Part II – Viscosity The diameter and weight of five of the test spheres were measured and then the volume and density of each sphere were computed.
To get accurate result, this titration process are repeated for another two times. The entire procedure by which we obtain the molarity of a solution of one substance (NaOH) from an accurately known amount of another substance (KHP) is called standardization. The average molarity of the sodium hydroxide solution will be used in the next experiment. The second experiment is conducted to determine the molarity of acetic acid and mass percent in vinegar. 100mL of distilled water was added to 10mL of vinegar and followed by 1mL of NaOH was pour into the solution.