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.
Equipment List * Boiling Tube * 10 cm3 1mol dm-3 Hydrochloric Acid (HCL) * 15 cm3 1mol dm-3 Sodium Hydroxide (NaOH) * pH and Temperature Probes * Data Logger * Measuring Cylinder ‘ * Boiling Tube * Teat Pipette Method * Add 10ml of Hydrochloric acid, measured in a measuring cylinder, into a boiling tube. * Into a data logger, plug in both pH and temperature probes and switch on data logger. * Put in both the probes and measure both the temperature and pH before adding any other substances. * Add 1cm3 of Sodium Hydroxide, measured in a measuring cylinder, to the Hydrochloric acid, and
During this experiment soap will be created by placing 25 ml of vegetable oil, 20 ml of ethanol, and 25 ml of 6 M of sodium hydroxide into a 250 ml Erlenmeyer flask. The flask and contents are placed into a hot water bath for approximately 20 to 30 minutes. After boiling, the contents should form a paste like substance. Then the flask is placed into a ice bath to cool. While the flask cools, a vacuum filter is assembled using a Büchner funnel.
The excess acid will be reacted with sodium hydroxide to determine how much acid remains. The amount of acid that reacted with the eggshell and the amount of calcium carbonate in the eggshell itself will be determined using this data. Procedure: The volume of drops from dropping pipettes designated for acid and base was calculated by measuring the volume of 20 drops from each pipette in a graduated cylinder, then calculating the volume per drop. These pipettes were used in all other volume measurements. Eggshell was ground, and a mass of 0.1 gram was transferred to an Erlenmeyer flask.
I repeated the heating and measuring process 2 more times recording the masses in the data table. I then calculated the mass of the alum by subtracting the final mass of the cup and the alum from the mass of the cup. I then calculated the mass of the water
Hydrate Lab The purpose of this lab is to analyze the percent water in a crystalline hydrate and to indentify the hydrate from a list of possible unknowns. The solid hydrate will be heated to remove the water, and the percent can be found by measuring the mass of the solid before and after heating. The hydrate will be indentified by comparing the percent water in the hydrate with the percent water calculated for the possible unknown. Before the lab there are pre-lab questions: 1. Describe the three general safety rules for working with a Bunsen burner.
* Then you will have to put the test tube in a water bath and leave it until the contents reach the same temperature as the water bath. * Then you will have to take the thermometer from the test tube and put a glass rod into it instead. * After this you will have to use a 2cm syringe to measure out 1cm of lipase to the beaker in the water for the temperature you are investigating. * Then add the lipase to the test
After the effervescence, (15mL) of concentrated HCl was added drop wise to the solution. The mixture was then heated for 15 minutes in a boiling water bath. In two separate small beakers (20mL) of distilled water was placed in one and (20mL) of 6M HCl in the other. Both beakers were placed into an ice bath. After heating, the mixture was cooled to room temperature and filtered by vacuum filtration into a fritted funnel to yield a purple product.
So: mc(T1-T2)=MwCw(T2-Tw) Cw and c are the specific heats of the the water and material. Procedure: We had three different metals (aluminum, steel and brass) for this lab. We first boiled 1000g of water in a beaker on the hot plate and then submerged the metal object into the heated water. After allowing time for the metal to absorb the heat we removed the object and placed it in 100g of room temperature water in plastic cup. After shaking the cup gently to ensure that the mixture reached the equilibrium temperature quickly, we measured the final temperature to get the ‘T2' value.
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.