Answer:
Explanation:
The equation is given as:
CH3CHOHC2H4CHO + CH3OH --> CYCLIC ACETAL + H2O
This above equation is carried out in the presence of a strong acid. There are five mechanisms employed and they are:
Step 1:
Initial formation of the hemiacetal which takes several steps
Step 2:
Addition of a proton. The hemicetal is protonated on the hydroxyl group (-OH group)
Step 3:
As seen a bond is broken to give the H2O molecule and a resonance stabilized cation.
The carbonyl group on the cation is enriched with the oxygen-18 got from the H2O molecule as seen in the mechanism.
Step 4:
An attraction occurs between electrophile and nucleophile i.e the stabilised cation and the lone paids of the methanol.
Step 5:
Finally, a proton (+) is removed from the molecule by a lone pair of electron on the methanol.
Attached are the Steps 1 - 5 mechanism below
Due to its small size, lithium has a high melting and boiling point.
<h3>
Why does lithium have high melting and boiling point explain?</h3>
With only one valence electron to contribute to the metallic lattice, lithium and potassium are both alkali metals. We could infer that the metallic bonding is less strong between the electron cloud and the larger potassium cation than it is in the lithium structure. This means that because lithium creates a smaller cation, the electrostatic force in this situation should be greater also Lithium has high ionization energy and a high melting and boiling point because of its small size. As a result, its crystal structure has an extremely high binding energy.
<h3>
Alkali metals</h3>
The chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium make up the alkali metals (Fr). They make up group 1, which is located in the s-block of the periodic table, along with hydrogen.
Learn more about alkali metals here:-
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Assuming a basis of 100 g of Kevlar, therefore the masses
are:
C = 70.6 g
H = 4.2 g
N = 11.8 g
O = 13.4 g
We know the molar masses are:
C = 12.01, H = 1.008, N = 14.01, O = 16.00
Calculating for the moles per element:
C = 70.6 / 12.01 = 5.88 mol
H = 4.2 / 1.008 = 4.17 mol
N = 11.8 / 14.01 = 0.84 mol
O = 13.4 / 16 = 0.84 mol
To get the empirical formula, the next step is to divide
everything by the smallest moles = 0.84. So:
C = 7
H = 5
N = 1
O = 1
Hence the empirical formula is:
C7H5NO
Ferns reproduce with spores which existed the longest in Earth history.
Gymnosperms reproduce with cones and has needle-like, waxy leaves.
Angiosperms reproduce with flowers and newest type of plant in Earth history.
<h3>How ferns, gymnosperm and angiosperm reproduce?</h3>
Ferns reproduce with spores that existed the longest in Earth, gymnosperms reproduce through the formation of cones having needle-like, waxy leaves whereas angiosperms reproduce with flowers which turns into seed. The newest type of plant in Earth history is also belongs to this group.
Learn more about spore here: brainly.com/question/1022692
Answer:
when high-energy particles from the sun are trapped by earth's magnetic field
Explanation:
it is produced by a "depression" in the Earth's magnetic field in that area, caused by the fact that the center of the Earth's magnetic field is deviated from its geographic center by 450 km. Such an anomaly is thought by some to be a side effect of a Geomagnetic Reversal. These radiation belts originate from the Earth's intense magnetic field that is the product of their rotation. That field traps charged particles (plasma) from the Sun (solar wind), as well as charged particles that are generated by interaction of the Earth's atmosphere with cosmic radiation and high-energy solar radiation.