4. Record the pH measurements in your table. 5. Rinse the beaker thoroughly, and pour into it another 25ml of tap water, and add 0.1M NaOH drop by drop, recording the pH changes in exactly the same way as for the 0.1M HCl. 6.
Since a beaker is being used, stirring the water consistently is necessary. 6. Record the melting point of alum. The powder will turn into a clear liquid. Determine the percent water in the crystals: 1.
Obtain an Erlenmeyer flask that has a vacuum opening and attach the vacuum tube to it 8. Insert funnel and rinse the funnel with distilled water 9. Turn vacuum on and pour the pink solution into the Erlenmeyer flask, the precipitate should stay on top of the filter 10. Rinse the beaker out until all residue is gone 11. Try to rinse the precipitate in the funnel until the pink color is gone 12.
9. Draw blood into two microhematocrit tubes by capillary action avoiding air bubbles. The tubes should be filled about ¾ full and hold horizontally. 10. Wipe off excess blood from the capillary tube with a Kimwipe.
Data Case CH8. Q1. R&D expense for 2012: 1926 mln Revenue for 2012: 13 788 mln Q2. Total costs research facility: 24 mln. depreciation over 3 years Depreciation costs per year: 24/3= 8 mln per year.
Repeat steps 1-5 for trial 2. Variables and Control test: Independent Variable: Amount of each reactant poured into the test tubes Dependent Variable: Height of each solution Constant variables: Amount of time waiting for solution Data Table: Test tube # | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | Trial 1 | 0.5 cm | 1.0 cm | 1.1 cm | 1.5 cm | 1.5 cm | 1.5 cm | 1.3 cm | 1.5 cm | Trial 2 | 0.5 cm | 0.7 cm | 1.0 cm | 1.0 cm | 1.3 cm | 1.7 cm | 1.9 cm | 1.5 cm | Observation/Analysis: Solution turns yellow when a separate product is added, solid of the solution leaks down to the bottom after 20 minutes. Conclusion: The group tried to find the excess or limiting for the reaction between KI and Pb. In the end the hypothesis was supported by the data. We found that little amounts of each product led to a greater height of solids.
The first test tube will be control, the second will be substrate and indicator dye, the third will be dilute extract, the fourth will be the same contents as the second, the fifth will be medium concentration of extract, the sixth will be the same contents as the second, and the seventh will be concentrated extract. 3) Add stock solutions to each tube using the corresponding graduated 5 ml pipette or dispensing device. 4) Adjust the spectrometer to zero absorbance at 500nm. Pour contents of test tube 1 into a cuvette. ) Make sure to keep time, read the spectrometer, and record the data.
-Get six wooden splints that have been soaked in water. -Place them in the beaker half filled with water to continue soaking at your lab station. -Fill a second 250-mL beaker about half-full with tap water. Label this beaker “rinse water.” -Light the Bunsen burner. -Take one of the wooden splints and dip the soaked end in one of the metallic salts,
Press down on the curds with a paper towel to remove any extra moisture. Place them in the bowl and add several tablespoons of water. Stir the mixture until the lumps in the curds begin to dissolve and blend with the water. Add two teaspoons of baking soda and continue
Make sure the rubber stopper is securely in place since gas can easily leak out. Collecting the gaseous product: Prepare the gas collection bottle by positioning the bottle so that its mouth is. directly over the hole at the bottom of the trough; this is where the gas will enter the bottle. After the reaction, slide a square of glass over the mouth of the bottle while the bottle is still under water. Keeping the glass fixed to the mouth, raise the collection bottle and invert.