Materials: 3 beakers Thermometer 3 Alka-Seltzer tablets Stopwatch Mortar and pestle Source of hot water Ice cubes Graph paper Procedures: Hot water- Run water from the hot tap until it is hot as possible Fill beaker with 80 mL of hot water Use thermometer to take temperature of water. Record in data table. Remove 1 Alka-Seltzer tablet from package Drop into the water. Measure the time it takes for the tablet to completely dissolve. BE READY WITH THE STOPWATCH.
The experimenter used 3 identical plastic cups and filled one with room temperature tap water, one with warm tap water and one with boiling tap water. Each cup was placed into the freezer and was checked every 15 minutes for signs of freezing. The experimenter found that the room temperature water showed the first signs of freezing and in the final outcome froze solid before the water in the other cups. His findings showed that water containing impurities, such as tap water, will freeze faster based on a lower starting temperature. The second case study was covered in an article by Science News.
The Effect of Salt on the Boiling Point of Water Purpose: The purpose of this experiment was to test the effect of salt on the boiling point of water. Materials: Three 500 ML beakers Hot Plate Weighing cup Scale Salt Distilled water Thermometer Stirrer Hypothesis: If more salt is added to water then, the boiling point will increase. Independent variable: The dependent variable is the amount of salt put into each beaker filled with 200 ML of water. Dependent Variable: The dependent variable of this experiment is the boiling point of all the different beakers. Control: The control of this experiment is the one beaker filled with 200 ML of water and no salt.
Reaction II For the second reaction, we need 25 mL of 0.005 M lead nitrate and a clean 50 mL graduated cylinder. Add 1.4 mL of 0.25 M potassium iodide (we used 30 drops) into the flask. Pour the solution into the vacuum flask. Decant the solution evenly into two beakers. For the first beaker, we add 1 mL of 0.1 M potassium phosphate.
In the second beaker, place two ice cubes and add water to the 100 mL mark on the beaker. Then add the thermometer Celsius. Record the initial temperature of the water in both beakers. Make one data table incorporating both data sets (tap water and ice cube water) using 30 second time intervals and the temperature in degrees. Place both beakers on the hot plate and turn the hot plate to high.
First I made a water bath by filling the 100 mL beaker with cool tap water. I then placed crushed ice in the 100 mL beaker so the water level was just below the top of the beaker. I sprinkled a little salt in the ice water and mixed it well. I then filled the test tube half full with distilled water and set the test tube in the 24 well plate. I inserted the digital thermometer into the test tube and took reading every 30 seconds until the readings remained constant.
The samples don’t have to have the same mass as long as it’s between 0.3 and 0.4g. Add about 20mL of water and 3 drops of phenolphthalein indicator to each sample and allow the solid to dissolve. Prepare a 50mL buret for use by washing it, rinsing it with tap water, and rinsing it twice with distilled water. Finally rinse it twice with 5mL portions of your sodium hydroxide solution. Mount the buret on the ringstand and fill it above the zero mark with the prepared sodium hydroxide solution.
The reflux apparatus was place in the aluminum block. The block had been heated around 15 minutes which was to 120-130°C As the mixture was warmed, the white solid that formed was dissolved. The apparatus was lifted out of the aluminum block after a period of heating. Also, the flask was placed under the tap water to cool down the mixture to room temperature. Carefully 0.5mL increments of 3M sulfuric acid was
To dissolve the sodium chloride in the deionized water, we placed a magnetic stirrer into each beaker and placed it on the electric stirrer. Right before titration for each beaker containing the dissolving sodium chloride, we added the indicator - K2CrO4. Afterwards, the titrant was added in dropwise amounts. During titration, the solution changed colors from yellow to white. As the titrant was being added into the solution, there was a noticeable red spot at the point of impact between the solution and the titrant drop.