For which of the following molecules or ions does the following description apply? "the bonding can be explained using a set of sp 2 hybrid orbitals, with one of the hybrid orbitals holding a nonbonding pair of electrons."for which of the following molecules or ions does the following description apply? "the bonding can be explained using a set of sp 2 hybrid orbitals, with one of the hybrid orbitals holding a nonbonding pair of electrons." co2

h2s

o3

co3^2−

more than one of the above

O₃

Explanation:

Consider the molecule CO₂. The carbon is sp hybridized. Carbon has 4 valence electrons and oxygen contributes 2 electrons, 1 for each C=O which indicates that there are 8 electrons around the carbon. Since there are 4 bonds all of them are bond pairs. Each C=O double bond uses 2 bond pairs which are considered as single unit. These two double bond units try to get as far apart as possible making the molecule adopt a linear geometry.

Considering the H₂S molecule both oxygen and sulfur are the in the same group, which means both have a valence of 6. The four valence orbitals of sulfur, one 1 s orbital and three 3p orbitals mix together and forms four sp³ hybridized orbitals. Of the four hybridized orbitals, two overlaps with the 1s orbital of hydrogen forming 2 (S - H) bonds while the other two sp³ orbitals remain on sulfur which has lone pair of electrons. Because of the presence of lone pair, the angle between H-S-H bond is slightly less than the ideal tetrahedral bond angle. Thus, H2S having 2 bonding electron pair and 2 lone pairs has a bent shape.

Considering O₃ and according to the VSEPR theory ozone molecule must have a trigonal – planar geometry. It has a total of 18 valence electrons. From the resonance structure given below it is clear the 4 pairs of electrons exit as bonding pair, sp² or σ- bond and the remaining 10 electrons exit as lone pair. Of the three un- hybridized p orbitals one is anti – bonding and remains empty. In ozone the π bond is distributed between the two bonds, and each receives half a π bond. For this molecule the electron pair geometry is trigonal planar but the molecular geometry is bent. The presence of lone pair exerts slight repulsion on the bonding oxygen atoms and a slight compression of the bond angle greater than 120°.

In carbonate ion, the carbon is sp² hybridized. The carbon has 4 valence electrons and there are four bonds to the oxygen which add another 4 making a total of 8. There are 4 pairs of bonding electrons and no lone pair. Of the 4 bond pairs, 2 pairs are used in forming double bond C=O and 2 bond pairs in forming the two C-O single bonds., Thus CO₃²⁻ adopts a trigonal planar geometry.

Of the two molecules only ozone and carbonate ion, have sp2 hybridized central atoms. In ozone the central atoms have lone pair of electrons the hybridization around is sp². Hence the correct option is O₃

according to the u.s. department of agriculture, the label of "certified organic" comes with a set of highly regulated standards for environmental stewardship and resource conservation. some of these include maintenance and improvement of soil quality, prevention of ground and surface water contamination, greenhouse gas regulation, encouragement of biodiversity and conservation of water and energy (see references 1). organic practices integrate natural methods such as mulching, plant diversity, native and adapted plants, crop rotation and the introduction of beneficial insects to control pests without synthetic pesticides.

environmental implications of pesticides

synthetic pesticides ensure high crop yields. while effective in achieving this goal, pesticides contaminate soil, air, ground and surface water, as well as the plants and animals that come into contact with these contaminated sources. freshwater and marine organisms are particularly susceptible to pesticides through agricultural runoff. pesticides also reduce soil fertility (necessitating the use of synthetic fertilizers) and can travel far from the original source, contaminating water and air hundreds of miles from the location of application (see references 2).

health implications of organics

although a subject of particular debate, many recent findings show that organic food is healthier than conventionally grown food. according to the usda, an extensive european union-funded study found that organically grown foods contain more beneficial compounds, such as the vitamins and antioxidants needed to combat many diseases (see references 5). organic milk, meat and eggs are regulated to ensure they are free of hormones administered to conventional livestock and poultry.

health implications of pesticides

pesticides affect human health in three ways: through skin contact, inhalation and ingestion. acute and long-term exposure to pesticides can cause serious health problems for farmers who apply them. the majority of other people are affected by drinking contaminated water and eating contaminated marine life (see references 3). pesticides have been linked to neurological disorders, endocrine and reproductive disorders, immune system deficiencies and cancer. according to the world health organization, acute pesticide poisoning (app) is responsible for significant annual mortality, especially in developing nations (see references 4).

other important considerations

not every small farm or business owner can afford the costly certification process required to be considered "certified organic," even if the farm is not using chemicals. "transitional" farms include those that once used chemicals and are now transitioning to organic-only production. in addition, though organic farming methods offer obvious environmental benefit, an organic apple shipped from around the world creates a different set of environmental problems. locally grown food (particularly locally grown, organic food) is key in sustainable food production.