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zavuch27 [327]
2 years ago
12

Why melting and boiling points can be used as a way to check purity?​

Chemistry
1 answer:
jekas [21]2 years ago
6 0

Answer: Let's see why

Pure solid and liquid compounds possess sharp melting and boiling points. Therefore, melting and boiling points of a compound can be used as a criteria of purity. ... Sometimes during cooling minute quantity of the substance (solid which is being purified) is added to the solution to facilitate the initial crystallisation.

Explanation:

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The Haber Process is the main industrial procedure to produce ammonia. The reaction combines nitrogen from air with hydrogen mai
Firdavs [7]

Answer:

A) N_2(g)+3H_2(g)\rightleftharpoons 2NH_3(g).

B) Kc=0.0933.

C) 0.9 mol.

D) Increasing both temperature and pressure.

Explanation:

Hello,

In this case, given the information, we proceed as follows:

A)

N_2(g)+3H_2(g)\rightleftharpoons 2NH_3(g)

B) For the calculation of Kc, we rate the equilibrium expression:

Kc=\frac{[NH_3]^2}{[N_2][H_2]^3}

Next, since at equilibrium the concentration of ammonia is 0.6 M (0.9 mol in 1.5 dm³ or L), in terms of the reaction extent x, we have:

[NH_3]=0.6M=2*x

x=\frac{0.6M}{2}=0.3M

Next, the concentrations of nitrogen and hydrogen at equilibrium are:

[N_2]=\frac{1.5mol}{1.5L}-x=1M-0.3M=0.7M

[H_2]=\frac{4mol}{1.5L}-3*x=2.67M-0.9M=1.77M

Therefore, the equilibrium constant is:

Kc=\frac{(0.6M)^2}{(0.7M)*(1.77M)^3}\\ \\Kc=0.0933

C) In this case, the equilibrium yield of ammonia is clearly 0.9 mol since is the yielded amount once equilibrium is established.

D) Here, since the reaction is endothermic (positive enthalpy change), one way to increase the yield of ammonia is increasing the temperature since heat is reactant for endothermic reactions. Moreover, since this reaction has less moles at the products, another way to increase the yield is increasing the pressure since when pressure is increased the side with fewer moles is favored.

Best regards.

7 0
3 years ago
Show how you might synthesize this compound from an alkyl bromide and a nucleophile in an SN2 reaction. Use the wedge/hash bond
PolarNik [594]

Answer:

See the image 1

Explanation:

If you look carefully at the progress of the SN2 reaction, you will realize something very important about the outcome. The nucleophile, being an electron-rich species, must attack the electrophilic carbon from the back side relative to the location of the leaving group. Approach from the front side simply doesn't work: the leaving group - which is also an electron-rich group - blocks the way. (see image 2)

The result of this backside attack is that the stereochemical configuration at the central carbon inverts as the reaction proceeds. In a sense, the molecule is turned inside out. At the transition state, the electrophilic carbon and the three 'R' substituents all lie on the same plane. (see image 3)

What this means is that SN2 reactions whether enzyme catalyzed or not, are inherently stereoselective: when the substitution takes place at a stereocenter, we can confidently predict the stereochemical configuration of the product.

6 0
3 years ago
A student notices that after two chemicals are mixed together the temperature of the mixture is higher than the temperature of t
swat32

Answer: exothermic

EXPLANATION: any process in which heat energy is released is called an exothermic process. For example burning of wood produces heat, so combustion of wood is an exothermic process.

When chemicals were not mixed they were at room temperature and when we mix them exothermic reaction took place and heat was released which raised the temperature of mixture.

7 0
3 years ago
What is the molecular weight (rmm) of NaOH?<br> 40<br> 20<br> 50<br> 60
Molodets [167]

Answer: A/40 it is actually 39.997 but since that is not an answer they rounded up

Explanation:

4 0
2 years ago
How many grams of N2 are in 44.8L at STP?
lutik1710 [3]

Answer: 10 i think

Explanation:

3 0
3 years ago
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