Magnesium is obtained from sea water. ca(oh)2 is added to sea water to precipitate mg(oh)2. the precipitate is filtered and reacted with hcl to produce mgcl2. the mgcl2 is electrolyzed to produce mg and cl2. if 185 g of magnesium are recovered from 962 g of mgcl2, what is the percent yield for this reaction? answer in units of percent

The percentage yield of magnessium is 19.231 %

Explanation:

The magnesium from sea water is added to Ca(OH)2 to precipitate Mg(OH)2. This magnesium hydroxide is then reacted with HCl as follows ;

Mg(OH)2 + 2HCl → MgCl2 + 2H2O

molar mass of MgCl2 = 24.305 + 35.453 × 2 =  24. 305 + 70.906 = 95.211 g

The equation is balanced now . And 1 mole or 95.11 g of MgCl2 was produced . The magnesium chloride was electrolyzed   to produce Mg and Cl2.

The total mass of MgCl2 obtained = 962 grams

mass of the Mg obtained  = 185 grams

The percentage yield for the magnesium  = 185 / 962 × 100 = 18500/962

The percentage yield for the magnesium  = 185 / 962 × 100 = 19.231 %

The percentage yield of magnessium is 19.231 %

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

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.