The effects of the ingestion of hot and cold fluids on the oral and axillary temperatures of a group of healthy individuals. Introduction The purpose of this experiment was to investigate how the ingestion of hot and cold fluid affects the oral and axilla temperatures of a group of 25 volunteers. The group started by establishing their oral and axilla baseline temperatures using a digital thermometer measured in degrees Celsius (°C). They then dissolved an ice cube in their mouths and re-took their temperatures at both locations. After fifteen minutes the volunteers then ingested a hot drink and re-took their oral and axilla temperatures.
* Document the time it takes .I will repeat the process three times and take the average amount of time it took for the solute to dissolve in the solvent of high temperature. * Secondly I will start the second experiment with moderate amount of temperature for example the temperature of the solvent could be half of the temperature of the previous experiment and follow the same steps. * Finally for my third experiment, I will use cold tap water and follow the above steps and compare my findings by filling the results in the table. I also make sure that equal amount of solute and solvent added in to the container to make my findings more accurate. The table below shows the result of the experiment Time taken for sugar to dissolve (sec) | Volume of water | Temperature of water | 1st result | 2nd result | 3rd result | Mean result
• After the flask was heated, I removed it from the heating mantel and allowed it to cool to room temperature. • Next, I poured 15mL of absolute ether and 9mL of bromobenzene into the 250mL flask and waited 5 minutes for any reaction. • There were no signs of reaction after 5 minutes; therefore the lab assistant used a glass stirring rod to crush the magnesium in order to get the reaction started. When this was done, the liquid became cloudy, rapidly bubbling, and the color turned rusty red. • Next, I added 25mL of absolute ether and attached a reflux condenser to the flask.
Part 1: Scemario 4 Carmen conducted an experiment to determine whether salt added to a cup of water affects its freezing point (the temperature at which it freezes). After some research, she hypothesized that the greater the amount of salt dissolved in the water, the lower the temperature at which the water freezes. Water samples were prepared containing equal quantities of water at the same starting temperature. Each sample received a different amount of salt and was placed into a freezer. The length of time it took for each sample to freeze was recorded as shown below.
A stopper was placed on the flask while the mixture was stirring with stirrer for 11/2 hours. After the mixture had been stirred the flask was wrapped in foil and place inside the freezer overnight. After the mixture had been frozen overnight and thawed it was then filtered on a Buchner Funnel and the flask was rinsed with ethanol and recrystallized. To recrystallize, the crystals that were formed after being filtered were redissolved in about 500mL of warm ethanol because of the 4-Chlorobenzaldehyde used, and it was placed in an ice bath. After the crystals were formed they were filtered on a Buchner Funnel, they were let dry over night, and were weighed after they had dried.
The normality of the unknown base is calculated after the solution has reached the end point. The amount of substance being delivered is calculated in units of equivalents per litre using the formula: VaNa = VbNb Experimental In order to titrate the acid with the unknown base, a solution of the acid was prepared. 5.1722 (±10%)g of potassium hydrogen phthalate acid is obtained using a weighing boat and transferred into a volumetric flask containing 250mL of boiled distilled water. Volumetric flask was shaken several times in order to assist the powder to dissolve. Once dissolved, 24.9734 (± 0.0045)mL of acid was pipetted into an Erlenmeyer flask along with 25mL of cool (recently boiled) distilled water.
Also, we watched as the water boiled and made observations as the temperature as it started to boil. This is done on a Virtual Lab. Materials: (Virtual Lab) * Water * Ice * Water-heating device or heater * Metals(Aluminum, Steel, Copper, Lead) * Electrical Balance Procedures: SPECIFIC HEAT OF METALS: * Weigh the mass of the metal samples * Fill up the calorimeter to 100mL. It should be at 25C * Heat up the Aluminum Sample to 200C * Drop the Aluminum Sample in the water and record the temperature changes. * Repeat with the rest of the samples.
A graph for the data was also set up with time on the x axis in .5 second intervals and temperature on the y axis. The first task required the freezing point of pure p-xylene be determined. This was done by pipetting approximately 2ml of p-xylene into a polypropylene test tube. The dry thermistor probe was inserted into the p-xylene test tube which was then inserted into an ice water bath. The temperature probe was used to stir the p-xylene and ensured an accurate reading.
I then measured hot tap water versus boiling water, and then cold tap water versus water with ice, and recorded the temperature that was read on the thermometer, and then converted the temperature from Celsius (C), to Fahrenheit (F), and Kelvin (K). To understand how to measure mass, the lab required the following material: pen or pencil, 5 pennies, 3 quarters, 4 dimes and a key. Then I used the digital scale to measure the following objects to obtain its mass and recorded the data. For exercise 2, volume, density and concentration, I started off measuring the graduated cylinder to get its mass. From that mass, I was
We weighed the resulting powder to be 3.228 grams. We then transferred the powder nutmeg into a 50 ml round bottom flask and added 15 ml of dichloromethane. We placed our flask in to a standard heat reflux apparatus and gently refluxed the mixture. We waited until we saw the first drip of liquid in the apparatus and heated for 15 minutes. After the mixture was heated, there was solid on the bottom and liquid on the top of the flask.