Answer:
Agriculture was practiced for thousands of years without the use of artificial chemicals. Artificial fertilizers were first created during the mid-19th century. These new agricultural techniques, while beneficial in the short term, had an Institute of Plant Industry to improve traditional farming methods in India.
Explanation:
Polyethylene is synthesized from ethylene which is a compound derived from natural gas or petroleum. It’s essentially a thermoplastic, implying that it can be molten and remolded into the desired shape making it reusable and cost-effective. Of all the different kinds of plastics produced around the world, polyethylene is the most common and significant.
Polyethylene is manufactured in three different forms namely:
Low Density Polyethylene (LDPE),High Density Polyethylene (HDPE) andLinear Low Density Polyethylene (LLDPE),
Each of these three plastics has different applications ranging from containers, packaging and films to buckets and bottles.
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Answer:
- <em>Hydration number:</em> 4
Explanation:
<u>1) Mass of water in the hydrated compound</u>
Mass of water = Mass of the hydrated sample - mass of the dehydrated compound
Mass of water = 30.7 g - 22.9 g = 7.8 g
<u>2) Number of moles of water</u>
- Number of moles = mass in grams / molar mass
- molar mass of H₂O = 2×1.008 g/mol + 15.999 g*mol = 18.015 g/mol
- Number of moles of H₂O = 7.9 g / 18.015 g/mol = 0.439 mol
<u>3) Number of moles of Strontium nitrate dehydrated, Sr (NO₃)₂</u>
- The mass of strontium nitrate dehydrated is the constant mass obtained after heating = 22.9 g
- Molar mass of Sr (NO₃)₂ : 211.63 g/mol (you can obtain it from a internet or calculate using the atomic masses of each element from a periodic table).
- Number of moles of Sr (NO₃)₂ = 22.9 g / 211.63 g/mol = 0.108 mol
<u>4) Ratio</u>
- 0.439 mol H₂O / 0.108 mol Sr(NO₃)₂ ≈ 4 mol H₂O : 1 mol Sr (NO₃)₂
Which means that the hydration number is 4.
Answer:
In this section, we consider how several of the enumerated powers of Congress under the original Constitution have been interpreted. The Congress shall have Power To lay and collect Taxes, Duties, Imposts and Excises, to pay the Debts and provide for the common Defence and general Welfare of the United States.
Answer:
The atomic mass number is the number of protons and neutrons in an atom.