Oxygen
Oxygen and its compounds play a key role in many of the important processes of life and industry. Oxygen in the biosphere is essential in the processes of respiration and metabolism, the means by which animals derive the energy needed to sustain life. Furthermore, oxygen is the most abundant element at the surface of the Earth. In combined form it is found in ores, earths, rocks, and gemstones, as well as in all living organisms. Oxygen is a gaseous chemical element in
Group VA of the periodic table. The chemical symbol for atomic oxygen is O, its atomic number is 8, and its atomic weight is 15.9994. Elemental oxygen is known principally in the gaseous form as the diatomic molecule, which makes up 20.95% of the volume of dry air.
…show more content…
Several different structures are known for solid oxygen: solid type III, from the lowest temperatures achievable to 23.66 K; type II, from 23.66 to 43.76
K; and type I, from 43.76 to 54.39 K. The critical temperature for oxygen, the temperature above which it is impossible to liquefy the gas no matter how much pressure is applied, is 154.3 K (-118.9 deg C; -181.9 deg F). The pressure of liquid and gaseous oxygen coexisting in equilibrium at the critical temperature is 49.7 atmospheres. Oxygen gas exhibits a slight but important solubility in water. Molecular oxygen dissolved in water is required by aquatic organisms for their metabolic processes and is ultimately responsible for the oxidation and removal of organic wastes in water. The solubilities of gases depend on the temperature of the solution and the pressure of the gas over the solution. At 20 deg C (68 deg F) and an oxygen pressure of one atmosphere, the solubility of
O(2) in water is about 45 grams of oxygen per cubic meter of water, or 45 ppm
(parts per million). Molecular diatomic oxygen is a fairly stable molecule requiring a dissociation energy (the energy required to dissociate one mole of molecular oxygen in its ground state into two moles of atomic oxygen in its ground state) of 493.6 kilojoules per mole. The molecule is dissociated by ultraviolet radiation of any wavelength shorter than 193 nm. Solar radiation striking stratospheric oxygen dissociates it into atomic oxygen for this reason.
the test tube. On the temperature graph, the highest point was at 27ºC, which means that
Predict: If the added mass on the lid was 50 kg, a total mass of 60 kg would exert pressure on the gas inside the container. What would be the volume of the gas? __.42 ______________
Problem 1: A volume 10 m3 contains 8 kg of oxygen at a temperature of 300 K. Find the work necessary to decrease the volume to 5 m3, (a) at a constant pressure and (b) at constant temperature. (c) What is the temperature at the end of the process in (a)? (d) What is the pressure at the end of process in (b)? (e) Show both processes in the p-V plane. Problem 2: The temperature of an ideal gas at an initial pressure p1 and volume V1 is increased at constant volume until the pressure is doubled. The gas is then expanded isothermally until the pressure drops to its original value, where it is compressed at constant pressure until the volume returns to its initial value. (a) Sketch these processes in the p-V plane and in
1. Move the lid of the container up or down. Record the resulting volume and pressure
The dissolved oxygen level continued to drop until it went 2.9. Once it got bottomed out it started to rise again.
The solubility of Mg(OH)2 (Ksp = 8.9 10-12) in 1.0 L of a solution buffered (with large capacity) at pH 9.58 is:
Start Virtual ChemLab and select Boiling Point Elevation from the list of assignments. The lab
The ozone is a form of oxygen that combines three oxygen atoms in each molecule. Its important because its like a filter. CFCS, also known as, chlorofluorocarbons are used to break up some of the ozone molecules
Mass of oxygen = final mass - initial mass = 0.08 g - 0.06 g = 0.02 g
1. Start Virtual ChemLab and select Boyle’s Law: Pressure and Volume from the list of assignments. The lab will open in the Gases laboratory.
Oxygen is a highly reactive nonmetal, and is an oxidizing agent (process of a substance combining with oxygen, like rust). Oxygen has the second highest electronegativity; electronegativity is a measure of the tendency an atom to attract with a bonding pair of electrons with oxygen’s electronegativity at 3.44. Oxygen is can be a clear, tasteless and odorless gas, or a pale-blue liquid. Oxygen will condense at -297.31 °F, and will freeze at -361.82 °F. Oxygen is a poor conductor of heat and electricity, and is somewhat soluble in water. Oxygen is denser than air- with a density of 1.429 G/L-
percent by weight of the oceans and, as a constituent of most rocks and minerals,
The hydrochloric acid is put into a calorimeter and then the zinc is added after. The lid is closed after the zinc is added and a thermometer is inserted through the lid in order to check the temperature as the reaction takes place . The temperature is measured until the reaction has completed and the highest temperature is used as the final temperature. ∆T is then found by the equation ∆T=Tfinal-Tinitial. Then according using the equation ∆H=mc ∆T+PV. In this lab the pressure remains constant while the volume is changing. In order to calculate the volume the same reaction with the same amount of zinc and hydrochloric acid is used. However, instead of a calorimeter, an erhlenmeyer flask with a balloon put over the top is used. The hydrochloric acid is placed into a flask, the zinc is placed inside the balloon and then sealed over the flask. By dropping the zinc into the flask the reaction occurs. This allows the H₂ gas to be captured in the balloon. The circumference of the balloon is then found. The circumference can then be applied to the equation C=2πr and the radius is determined. Using the radius of the balloon, in the equation V=(4/3)πr³ the volume taken up by the hydrogen gas can be found. The pressure is the pressure of the air which is measured with a barometer. ∆H can be found by multiplying the mass of hydrochloric acid, the specific heat of HCl, and ∆T of the hydrochloric
“Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table and is a highly reactive non metal and oxidizing agent that readily forms oxides with most elements as well as other compounds.”By mass, oxygen is the third-most abundant element in the universe, after hydrogen and helium. At standard temperature and pressure, two atoms of the element bind to found dioxygen, a colorless and odorless diatomic gas with the formula O2. This is an important part of the atmosphere and diatomic oxygen gas constitutes 20.8% of the Earth 's atmosphere. Additionally, as oxides the element also makes up almost half of the Earth 's crust.Oxygen is necessary to sustain most terrestrial life. Oxygen is used in cellular respiration and many major classes of organic molecules in living organisms contain oxygen, such as proteins, nucleic acids, carbohydrates, and fats, as do the major constituent inorganic compounds of animal shells, teeth, and bone. Most of the mass of living organisms is oxygen as a component of water, the major constituent of lifeforms. Conversely, oxygen is continuously replenished by photosynthesis, which uses the energy of sunlight to produce oxygen from water and carbon dioxide. Oxygen is too chemically reactive to remain a free element in air without being continuously replenished by the photosynthetic action of living organisms. Another form (allotrope) of oxygen, ozone (O
Chlorine peroxide (also identified as dichlorine dioxide or dimer) is a molecular compound with method ClOOCl. Chemically,this is a dimer of the chlorine monoxide radical (ClO). It is dynamic in the development of the ozone hole. Chlorine peroxide catalytically changes ozone into oxygen when it is visible by infrared light.