Name: Sonoma Bryan
Partner: Matthew Cleveland
Drawer Number: 18
Thermochemistry Lab
Chemistry 101
Section: CHE 101-002
04/14/14
Thermochemistry is the study of the heat associated with chemical reactions and physical processes heat changes that accompany physical and chemical processes. (textbook) During the first portion of this lab the caloric content of a snack food was found by burning it and measuring how much heat was released. For the second part of this lab, a styrofoam calorimeter was used to measure the specific heat of an unknown metal and that information was used to identify the sample. A calorimeter is a tool used in thermochemistry can be used to measure the heat exchanged between the system and surroundings for a variety of reactions.
Specific heat: The specific heat (s) of a substance is the amount of heat required to raise the temperature of 1 g of the substance by 1°C.()
Some of unfamiliar units that are used in this lab are Joules, calories, and Calories. All of these units measure energy, heat, and work.
I Joule=4.18 calories 1 Calorie or kcal=1,000 calories
Safety
Aluminum is slightly hazardous in case of skin contact (irritant), non-hazardous in case of ingestion, and non-hazardous in case of inhalation.
Lead is slightly hazardous in case of skin contact (irritant), of ingestion, and of inhalation. May also cause damage to the following organs: blood, kidneys, central nervous system
Zinc is slightly hazardous in case of skin contact (irritant), of ingestion, and of inhalation.
Nickel is hazardous in case of inhalation, slightly hazardous in case of skin contact (irritant, sensitizer), and of ingestion. May also cause damage to the following organs: kidneys, lungs, liver, and upper respiratory tra...
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...at from the metal was lost from the transfer of the metal from the test tube submerged in the boiling water to the water in the calorimeter. This loss of heat would have lowered the temperatures that were measured, and overall made it seem like the substances that were being observed were releasing less heat then they actually were capable of. Another more specific source of error that was encountered, was during the first snack trial. The chip that was used was curled and needed relighting several times. This addition of heat to the system of the water was not from the chip burning, but from the lighter that was used. This means that during the first trial in the snack burning portion of the lab the change in heat recorded was higher than it should have been. This means that it was recorded that the chip was outputting more energy than we could conceivably measure.
Thermodynamics is essentially how heat energy transfers from one substance to another. In “Joe Science vs. the Water Heater,” the temperature of water in a water heater must be found without measuring the water directly from the water heater. This problem was translated to the lab by providing heated water, fish bowl thermometers, styrofoam cups, and all other instruments found in the lab. The thermometer only reaches 45 degrees celsius; therefore, thermodynamic equations need to be applied in order to find the original temperature of the hot water. We also had access to deionized water that was approximately room temperature.
Lead is a metal found virtually everywhere even today. Sources of lead include auto body shops, electric storage batteries, glazes for china dishes, crockery, insecticides, electric cable insulation, hose, pipe, sheet and floor coverings. Lead is associated with stain glass work, jewelry making and antique ceramic doll painting. Although lead in paint was outlawed, there are still many homes that have lead paint (White et al, 1990). Lead found in gasoline was found in one study to account for 23--27% of the lead blood levels in the people tested (Wagner, 1991). This exposure to lead sources is more of a concern for children due to the characteristic habit of children to taste everything they touch; this characteristic is known as pica. Children are also in closer contact with their lead polluted environment during play. They are more active and exposed to outdoor contaminates and they inhale dust and dirt that are lead contaminated. Furthermore, the adsorption rate of lead in the digestive tract is up to 10 times greater in chil...
...and MEA. These chemicals are said to be linked with breast cancer, skin rashes, estrogenic, hormone disruptor, linked to liver and kidney cancer, and irritates the eye.
In this lab, I determined the amount of heat exchanged in four different chemical reactions only using two different compounds and water. The two compounds used were Magnesium Hydroxide and Citric Acid. Both compounds were in there solid states in powder form. Magnesium Hydroxide was mixed with water and the change in heat was measured using a thermometer. The next reaction combined citric acid and magnesium hydroxide in water. The change in heat was measured as well. For the third reaction citric acid was placed in water to measure the change in heat. In the last reaction, citric acid was combined with water. The heat exchanged was again measured. It is obvious we were studying the calorimetry of each reaction. We used a calorimeter
...f inorganic arsenic may be a danger to human health. The exposure to arsenic is higher for people who work with arsenic, also for people who drink significant amounts of wine. People living in houses that contain wood preservatives, and live on farms where arsenic pesticides have been applied in the past are highly exposure.
on how long it takes to heat up. If we heat a large volume of water it
Direct contact of skin with the high concentration of compounds of inorganic arsenic present in the soil may cause skin irritation with some swelling and redness. But is does not appear that the direct skin contact may lead to any serious internal infections.
Examples of these adverse effects are developmental disabilities, interruption of human growth and development, and depletion of the central nervous system in a child (Overview, n.d.). As noted by Overview (n.d.), “When absorbed into the human body, lead affects the blood, kidneys and nervous system. Lead’s effects on the nervous system are particularly serious and can cause learning disabilities, hyperactivity, decreased hearing, mental retardation and possible death” ( p.
There are many contributing factors that enhance the amount of lead in the environment, for instance, environmental lead occurs from the burning of leaded gasoline, from battery and smelter industries and it’s also found in ink and paper. Additionally, many canned food products are sealed with lead solder (Analytical Research Laboratories, 2012). Due to the vast quantity of lead found in the environment, exposure is inevitable. On the contrary, there are three main ways in which lead can enter the body: inhalation, ingestion or absorption through the skin. It may be inhaled when it is burned or melted, releasing some of the lead as a fume and or when dust that contains lead becomes airborne. In terms of ingestion, lead may be ingested through drinking water, when dust particles containing lead come in contact with food or food preparation surfaces, etc. In particular cases that inv...
This section gives information on toxicity of substance and health effect, defines the medical signs and symptoms that may be encountered with normal exposure or overexposure to the material or its components. In this section tell about rout of chemical hazarded include inhalation skin and eye contact , description of effect from short and long term exposure. Data should be included for acute, sub chronic and chronic exposures, if available.
Mroszczyk (2012) advocate that there are four main routes of exposure by which chemicals can contact and/or enter a body. Many chemicals can cause direct effects at the point of contact, such as irritation of the skin, eyes, mouth or nose. Some chemicals can also be absorbed into the body and cause harmful effects on other body systems like the blood, liver or nervous system.
To answer the most obvious question, what is ΔHºrxn·? Well, ΔHºrxn· means the change in enthalpy. To break it down further, enthalpy is the measure of the amount of energy in a system. Every single reaction in the entire universe has a change in enthalpy. Energy is held in each and every single bond that puts together the world we see and live in today. When a reaction takes place and bonds are broken and reconnected, energy has been transferred, and enthalpy tells us how much. It is just about nearly impossible to measure all of the energy that there is out there, but scientists can measure how much energy has been transferred through the system. It would be like trying to measure the volume of the ocean, pretty much impossible, huh? But,
In chemistry, Colorimetry is used a lot. They use it for things such as colour painting, food manufacturing, and textiles. Colorimetry can also be used to measure light. The amount of light absorbed is called and also is measured as the absorbance which is a use of the coloured solute concentration. To use a colorimeter, different kinds of solutions have to be made, this includes a regulator or orientation of identified concentration.
Thermodynamics is the branch of science concerned with the nature of heat and its conversion to any form of energy. In thermodynamics, both the thermodynamic system and its environment are considered. A thermodynamic system, in general, is defined by its volume, pressure, temperature, and chemical make-up. In general, the environment will contain heat sources with unlimited heat capacity, allowing it to give and receive heat without changing its temperature. Whenever the conditions change, the thermodynamic system will respond by changing its state; the temperature, volume, pressure, or chemical make-up will adjust accordingly in order to reach its original state of equilibrium.
The study of the relation between internal energy, heat, and work is the basic foundation in thermodynamics. How they interact can be applied to mechanics and experiments. For example, if you add heat to a piston, the gas contained inside will begin to expand and cause displacement, doing work. Gases are heavily studied in thermodynamics, because the internal energy is easier to account for. Gases only have kinetic energy because the potential energy is negligible since the far apart molecules cannot interact with each other. The four main types of thermodynamic processes- isovolumetric, isothermal, adiabatic, and isobaric-all involve the relation between work, heat, and internal energy on gases.