Chem 100 chapter 2

Mesosphere

3rd layer of the atmosphere

Organic compounds always have the element?

Carbon

macroscopic view of matter

Characteristics that can be described in this viewpoint are properties such as color, odor, chemical reactivity, or density. However, we can also describe matter using symbols. As we saw in Chapter 1, these descriptions use letters and numbers within chemical formulas to represent samples of matter (H2O for water, for example).

Even at concentrations well below 1 ppm

For instance, consider the following: Carbon monoxide CO has earned the nickname "the silent killer" because it has no color, taste, or smell. When you inhale carbon monoxide, it passes into your bloodstream and then interferes with the ability of your hemoglobin to carry oxygen. If you breathe carbon monoxide, at first you may feel dizzy and nauseous or get a headache—symptoms that could easily be mistaken for another illness. Continued exposure, however, can make you extremely ill or kill you. Propane-fueled camping stoves (Figure 2.8) can be another.

Particulate view of matter

In this view, we "see" or imagine what the actual particles, atoms, or molecules look like, and how they might interact (Figure 2.6).

Nitrogen Oxides (NOx)

NOx. Nitrogen dioxide NO2 has a characteristic brown color and is the primary visible component of urban smog, as previously shown in Figure 2.5b. Like sulfur dioxide, it can combine with the moist tissue in your lungs to produce an acid. In our atmosphere, nitrogen dioxide is produced from nitrogen monoxide (NO; common name: nitric oxide), another pollutant that is a colorless gas. Nitrogen monoxide is formed from the reaction of N2 and O2 in the air from anything that is hot, including vehicle engines and coal-fired power plants. Nitrogen oxides, NO and NO2, can also form naturally in grain silos and can injure or kill farmers who may inadvertently inhale the gases.

The air is different in a pine forest, a bakery, an Italian restaurant, and a dairy barn. Blindfolded, you could smell the difference. Our noses alert us to the fact that air contains trace quantities of many substances. Name three indoor and three outdoor smells that indicate small quantities of additional chemicals are present in the air.

Other chemicals you might smell in the air include cleaning products, rotting food, a burning candle, flowers blooming, freshly mowed grass, or the smell after a rainstorm.

Our noses warn us to avoid certain things. Give three examples of when a smell indicates a hazard or something to be avoided.

Smells that might alert us to a hazard include smoke, which is a mixture of gases released when something is burned; mercaptan, an additive to natural gas that gives it its "rotten egg" smell to alert you to a possible gas leak in your home; and acrolein, a toxic chemical produced when fats and cooking oils are heated for prolonged periods of time at high temperatures.

Exosphere

The outer layer of the thermosphere, extending outward into space.

Thermosphere

The outermost layer of Earth's atmosphere.

Resperation

The process by which cells break down simple food molecules to release the energy they contain.

Stratosphere

The second-lowest layer of Earth's atmosphere.

Particulate matter (PM)

is a complex mixture of tiny solid particles and microscopic liquid droplets, and is the least understood of the air pollutants that we have listed. Particulate matter is classified by size rather than composition, and its size is larger relative to the individual molecules we have described thus far (Figure 2.11). The sizes of the particles are inversely correlated with the severity of the health consequence. PM10 includes particles with an average diameter of 10 μm1.0×104 nm, or about one eigth the width of a human hair. PM2.5 is a subset of PM10 and includes particles with an average diameter of 2.5 μm2.5×103 nm or less. These tinier and more deadly particles are sometimes called fine particulates. Particulate matter originates from many sources, including vehicle engines, coal-burning power plants, wildfires, and blowing dust. Sometimes, particulate matter is visible as soot or smoke (Figure 2.12), but the two types described here, PM10 and PM2.5, are too tiny to see. These particles, when inhaled, go deep into your lungs and cause irritation, possibly even resulting in lung cancer. The smallest particles pass from your lungs into your bloodstream and can cause heart disease.

Trophosphere

layer of Earth's amosphere closest to Earth's surface (where weather takes place and where most pollution occurs) and wand accounts for 75% of the mass of the entire atmosphere.

What is air made up of?

nitrogen N2, oxygen , argon Ar, carbon dioxide CO2, and water

air inversions

occur when cooler air gets trapped beneath warmer air due to weather conditions in an area. Air pollutants can also accumulate in the cooler air of an inversion layer, especially if the layer remains stationary for an extended period. This often occurs in cities surrounded by mountains, such as Salt Lake City, Utah,

Lead

s a naturally occurring element found in small amounts in Earth's crust. Major sources of lead are ore and metal processing plants, cosmetics, waste incinerators, and plumbing materials, as well as lead-acid battery manufacturing and recycling facilities. Paint formulations once contained lead, but were banned in 1978; hence, renovations of older homes present a serious risk of lead exposure. Although the Environmental Protection Agency (EPA) banned lead-containing compounds from motor vehicle gasoline in the 1980s, the switch to unleaded aviation fuels finally occurred in 2018. When lead is released to the air, it may travel long distances before settling to the ground, where it may accumulate in soil or water reserves. Once inhaled or ingested, lead distributes throughout the body in the blood and accumulates in bones. Depending on the level of exposure, lead may adversely affect the central nervous system, immune system, reproductive and developmental systems, and the cardiovascular system. Infants and young children are especially sensitive to low levels of lead, which may contribute to behavioral problems and learning deficits. Although lead poisoning may be treated, any damage caused by lead exposure cannot be reversed.

A(n) what pollutant is produced from chemical reactions involving one or more other pollutants.

secondary

Organic molecules contain

skeleton structures of carbon with hydrogen and oxygen

combustion reaction

usually including oxygen and usually accompanied by the generation of heat and light in the form of flame.

Take a breath. What are you breathing in? Exhale. What are you breathing out? Is there an "ideal" atmosphere in which you might breathe? If so, provide a description.

We inhale a mixture of nitrogen, oxygen, argon, carbon dioxide, water, and other gases in trace amounts. We exhale a mixture of the same chemicals although the relative amounts of each chemical change; most notably the oxygen quantity decreases and the carbon dioxide quantity increases. An "ideal" atmosphere would consist entirely of N2 and O2 gases. However, the addition of other gases such as Ar, H2O and CO2 would not negatively affect our health and could therefore also be present in an ideal breath.

We live in an atmosphere of 21% oxygen. A match burns in less than a minute, a fireplace consumes a small pine log in about 20 minutes, and we exhale about 15 times a minute. Life on Earth would be very different if the oxygen concentration were twice as high. List at least four ways Earth or our lives might be different with such an increased amount of oxygen.

With an increased amount of oxygen in the atmosphere, corrosion would occur more quickly and combustion reactions would occur more readily and burn more efficiently. Although this may not seem detrimental in all aspects (think better gas mileage!), the global ramifications of this change would be enormous; things that previously only got hot or smoked, like burnt toast, would now readily catch on fire.

the composition of air by volume is

about 78% nitrogen, 21% oxygen, and 1% other gases. Percent (%) means "parts per hundred." In this case, the parts are either molecules or atoms.

What products may be formed when a hydrocarbon undergoes combustion? Select all that apply.

carbon monoxide (CO) heat and carbon dioxide (CO2)

Certain gases contribute to air pollution at the surface of Earth. One of these gases

carbon monoxide CO, is odorless; others—ozone O3, sulfur dioxide SO2, and nitrogen dioxide NO2—have characteristic odors. All can be hazardous to your health, even at concentrations well below 1 ppm.

Ozone O3

has a sharp odor that you may have detected around electric motors or welding equipment. Even at very low concentrations, ozone can reduce your lung function. The symptoms you experience may include chest pain, coughing, sneezing, or lung congestion. Ozone also mottles the leaves of crops and yellows pine needles (Figure 2.9). Here on Earth's surface, ozone is definitely a harmful pollutant. However, at high altitudes, it plays an essential role in screening harmful ultraviolet UV radiation, as you will learn in Chapter 3.

Sulfur dioxide SO2

has a sharp, unpleasant odor. If you inhale sulfur dioxide, it dissolves in the moist tissue of your lungs to form an acid. The elderly, the young, and individuals with emphysema or asthma are most susceptible to sulfur dioxide poisoning. At present, sulfur dioxide in the air comes primarily from the burning of coal. For example, the 1952 London smog that eventually killed over 10,000 people was in part caused by the SO2 emissions from coal-fired stoves. The causes of death included acute respiratory distress, heart failure (from preexisting conditions), and asphyxiation.

Hydrocarbons are compounds that contain only

hydrogen and oxygen