Caffeine is more soluble in dichloromethane and the both are separated by evaporating the solvent.
Caffeine is an organic plant material which is more soluble in non-polar solvents than in polar solvents. As such, caffeine is more soluble in dichloromethane than in pure water.
In order to carry out a liquid-liquid exaction of dichloromethane from a commercial teabag, the dichloromethane is mixed with water. The caffeine is found to be more soluble in the organic dichloromethane layer than in water.
The two solvents can now be separated using a separating funnel and the solution is evaporated to obtain the caffeine.
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A chemical element that has an atomic number less than 58 and an atomic mass greater than 135.6m is barium (atomic no. 56 and atomic mass137.13 ) and lanthanum (atomic no. 57 and atomic mass 135.6).
<h3>Give a brief introduction about Barium and Lanthanum.</h3>
Barium is an element with the symbol Ba and atomic number 56. It is an alkaline earth metal that is soft and silvery, and it is the fifth element in group 2. Barium is never found in nature as a free element due to its extreme chemical reactivity. Oil well drilling fluid uses barium sulfate as an insoluble ingredient. It is employed as an X-ray radiocontrast agent in a purer form to image the human gastrointestinal tract. Barium compounds that dissolve in water have been employed as rodenticides despite being hazardous.
Chemical element lanthanum has the atomic number 57 and the symbol La. It is a silvery-white, ductile, soft metal that slowly tarnishes when exposed to air. It serves as the eponym for the group of 15 related elements in the periodic table between lanthanum and lutetium, of which lanthanum is the first and prototype. The rare earth elements traditionally include lanthanum.
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Answer:
Explanation:
- For the balanced reaction:
<em>4Fe(s) + 3O₂(g) → 2Fe₂O₃(s).</em>
It is clear that 4 mol of Fe react with 3 mol of O₂ to produce 2 mol of Fe₂O₃.
- Firstly, we need to calculate the no. of moles of 35.8 grams of Fe metal:
no. of moles of Fe = mass/molar mass = (35.8 g)/(55.845 g/mol) = 0.64 mol.
- Now, we can find the no. of moles of O₂ is needed to react with the proposed amount of Fe:
<em><u>Using cross multiplication:</u></em>
4 mol of Fe is needed to react with → 3 mol of O₂, from stichiometry.
0.64 mol of Fe is needed to react with → ??? mol of O₂.
∴ The no. of moles of O₂ needed = (3 mol)(0.64 mol)/(4 mol) = 0.48 mol.
- Finally, we can get the volume of oxygen using the information:
<em>It is known that 1 mole of any gas occupies 22.4 L at standard P and T (STP).</em>
<em></em>
<em><u>Using cross multiplication:</u></em>
1 mol of O₂ occupies → 22.4 L, at STP conditions.
0.48 mol of O₂ occupies → ??? L.
∴ The no. of liters of O₂ = (0.48 mol)(22.4 L)/(1 mol) = 10.752 L.
Answer:
carbon dioxide
Explanation:
because we breath in oxygen and breath out Carbon
Answer:
1. There are so many ethical concerns about biotechnology, some Ethical issues that arise from the application of modern biotechnologies include:
Discrimination of individuals because of their health or health history as a result of knowing their genetic information, minimizing harms while maximizing benefits, Interference with nature, privacy.
2. a. Plants (maize, rice)
b. Fish (GloFish)
3. For individuals, biotechnology has helped in the prevention and treatment of a wide range of diseases. For society, biotechnology saves time, improves the health and quality of food through a reduction in the use of pesticides and it can create new viruses and bacteria that cause diseases. Biotechnology could address global change since more genetically modified plants are grown.
