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3 years ago

What purpose do each of the following play in the isolation and purification of ethyl 3- hydroxybutanoate?

Chemistry

1 answer:

Shalnov [3]3 years ago

8 0

Explanation:

-Filter help — delete some big unreacted, undesirable species (norit is probably from what you are sorting through, its only carbon which cleans up things)

— extract with DCM because you are probably in an aqueous phase, and some butanoate is in it

- Anhydrous sodium absorbs excess of water (dries the material)

-evaporation in the hood to clear the DCM and crystallize the product.

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Dolomite is a carbonate of magnesium and calcium. Analysis shows that 7.81 g of dolomite contains 1.70 grams of Ca. Fluorite is

andrew11 [14]

Answer:

The richer source of calcium is fluorite.

Explanation:

Percentage of element in compound :

$=\frac{\text{mass of element}}{\text{Mass of compound}}\times 100$

1. Dolomite is a carbonate of magnesium and calcium:

Given mass of dolomite = 7.81 g

Mass of calcium present in given mass of dolomite = 1.70 g

Percentage of calcium in Dolomite:

$=\frac{1.70 g}{7.81 g}\times 100=21.77\%$

2. Fluorite is a mineral of calcium and fluorine:

Given mass of fluorite = 2.76 g

Mass of fluorine present in given mass of fluorite = 1.34 g

Percentage of fluorine in fluorite :

$=\frac{1.34 g}{2.76 g}\times 100=48.55\%$

Percentage of calcium in fluorite = 100% - 48.55 % = 51.45%

Percentage of calcium in fluorite > Percentage of calcium in Dolomite

51.455 > 21.77%

So, the richer source of calcium is fluorite.

7 0

3 years ago

the isotope 146c has a half life of 5730 years. what fraction of 146c in a sample with mass ,m, after 28650 years

defon

Answer:

3.1% is the fraction of the sample after 28650 years

Explanation:

The isotope decay follows the equation:

Ln[A] = -kt + Ln[A]₀

<em>Where [A] could be taken as fraction of isotope after time t, k is decay constant and [A]₀ is initial fraction of the isotope = 1</em>

<em />

k could be obtained from Half-Life as follows:

K = Ln 2 / Half-life

K = ln 2 / 5730 years

K = 1.2097x10⁻⁴ years⁻¹

Replacing in isotope decay equation:

Ln[A] = -1.2097x10⁻⁴ years⁻¹*28650 years + Ln[1]

Ln[A] = -3.4657

[A] = 0.0313 =

<h3>3.1% is the fraction of the sample after 28650 years</h3>

<em />

3 0

3 years ago

Sulfur reacts with oxygen to form sulfur dioxide (so2(g), hf = –296.8 kj/mol) according to the equation below. what is the entha

Varvara68 [4.7K]

The answer is B <span>-296.8 KJ</span>

6 0

3 years ago

Read 2 more answers

An iron chloride compound contains 55.85 grams of iron and 106.5 grams of chlorine. What is the most likely empirical formula fo

mart [117]

Answer:

$FeCl_{3}$

Explanation:

$Moles =\frac {Given\ mass}{Molar\ mass}$

mass of Fe = 55.85 g

Molar mass of Fe = 55.85 g/mol

<u>Moles of Fe = 55.85 / 55.85 = 1</u>

mass of Cl = 106.5 g

Molar mass of Cl = 35.5 g/mol

Moles of Cl = 106.5 / 35.5 = 3

Taking the simplest ratio for Fe and Cl as:

1 : 3

The empirical formula is = $FeCl_{3}$

3 0

4 years ago

Which type of orbital will be occupied by the electrons of highest energy for the Si^4+ ground-state ion? 1. 2s 2. 3p 3. 4s 4. 4

Shtirlitz [24]

Answer: Option (5) is the correct answer.

Explanation:

It is known that the ground state electronic configuration of silicon is $[Ne]3s^{2}3p^{2}$ .

And, we know that when an atom tends to gain an electron then it acquires a negative charge and when an atom tends to lose an electron then it acquires a positive charge.

As $Si^{4+}$ has a +4 charge which means that it has lost 4 electrons. Hence, the electronic configuration of $Si^{4+}$ is $1s^{2}2s^{2}2p^{6}$ .

According to the Aufbau principle, in the ground state of an atom or ion the electrons fill atomic orbitals of the lowest energy levels first, before filling the higher energy levels.

As 2p orbital is filled after the filling of 2s orbital.

Therefore, we can conclude that 2p orbital will be occupied by the electrons of highest energy for the $Si^{4+}$ ground-state ion.

4 0

3 years ago