For each of the following i) write a skeleton equation
ii) write a correct balanced chemical equation
iii) classify reaction by type

1) calcium metal and water react, giving hydrogen gas and calcium hydroxide

2) aluminum metal quickly reacts with the oxygen in the air to produce aluminum oxide

3) hydrogen sulphate (sulphutic acid) and sodium hydroxide react, producing sodium sulphate and water.

4) sodium chloride and oxygen are produced by heating sodium chlorate.

5) silver nitrate and potassium phosphate react together producing silver phosphate and potassium nitrate.

6) aluminum oxide and copper metal are the products of a reaction between copper (II) oxide and aluminum metal.

7)magnesium and phosphorus (P4) react together, producing magnesium phosphide.

8) lead (II) nitrate and potassium iodide react producing lead (II) iodide a bright yellow precipitate and potassium nitrate which stays in solution.

1. Skeleton: Ca + H₂O ⇒ H₂ + Ca(OH)₂

Balanced: Ca + 2H₂O ⇒ H₂ + Ca(OH)₂

Type: Single displacement / single replacement

2. Skeleton: Al + O₂ ⇒ Al₂O₃

Balanced: 4Al + 3O₂ ⇒ 2Al₂O₃

Type: Synthesis

3. Skeleton: H₂SO₄ + NaOH ⇒ Na₂SO₄ + H₂O

Balanced: H₂SO₄ + 2NaOH ⇒ Na₂SO₄ + 2H₂O

Type: Double displacement / double replacement

4. Skeleton: NaClO₃ ⇒ NaCl + O₂

Balanced: 2NaClO₃ ⇒ 2NaCl + 3O₂

Type: Decomposition

5. Skeleton: AgNO₃ + K₃PO₄ ⇒ Ag₃PO₄ + KNO₃

Balanced: 3AgNO₃ + K₃PO₄ ⇒ Ag₃PO₄ + 3KNO₃

Type: Double displacement / double replacement

6. Skeleton: Cu(OH)₂ + Al ⇒ Al(OH)₃ + Cu

Balanced: 3Cu(OH)₂ + 2Al ⇒ 2Al(OH)₃ + 3Cu

Type: Single replacement / single displacement

7. Skeleton: Mg + P₄ ⇒ Mg₃P₂

Balanced: 6Mg + P₄ ⇒ 2Mg₃P₂

Type: Synthesis

8. Skeleton: KNO₃ + PbI₂ ⇒ KI + Pb(NO₃)₂

Balanced: 2KNO₃ + PbI₂ ⇒ 2KI + Pb(NO₃)₂

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.