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3 years ago

Look at the image below:

Chemistry

1 answer:

Dominik [7]3 years ago

5 0

In the given image, we can see two differently colored spheres joined together to form a combination and there are 5 such combinations.If each small sphere represents an atom, then each combination represents a molecule of a compound. This is because an element contains only similar type of atoms. A compound contains two or more different types of atoms.

Therefore, the figure is a molecule and a compound.

For this reason, statement B is true.

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Treatment of ethyl acetoacetate with NaOEt (2 equiv) and BrCH2CH2Br forms compound X. This reaction is the first step in the syn

valkas [14]

Answer:

See explanation below

Explanation:

In this reaction we have the ethyl acetoacetate which is reacting with 2 eq of sodium etoxide. The sodium etoxide is a base and it usually behaves as a nucleophyle of many reactions. Therefore, it will atract all the acidics protons in a molecule.

In the case of the ethyl acetoacetate, the protons that are in the methylene group (CH3 - CO - CH2 - COOCH2CH3) are the more acidic protons, therefore the etoxide will substract these protons instead of the protons of the methyl groups. This is because those hydrogens (in the methylene group) are between two carbonile groups, which make them more available and acidic for any reaction. As we have 2 equivalents of etoxide, means that it will substract both of the hydrogen atoms there, and then, reacts with the Br - CH2CH2 - Br and form a product of an aldolic condensation.

The mechanism of this reaction to reach X is shown in the attached picture.

3 0

4 years ago

Draw the structures of organic compounds a and b omit all by products thf

Brums [2.3K]

The reaction is shown below,

Step 1: Hydration of Alkene:
In first step Ethene is hydrated to Ethanol through Hydroboration Reaction.

Step 2: Oxidation of Primary Alcohol:
In this step partial oxidation of ethanol is carried out using mild Oxidizing agent Pyridinium chlorochromate (PCC) and Acetaldehyde is produced.

Step 3: Reduction of Acetaldehyde followed by Oxidation:
In this step, first acetaldehyde is reduced to secondary alcohol using grignard reagent. After that the sec. alcohol is oxidized to ketone by using oxidizing agent CrO₃.

6 0

4 years ago

How many moles of gas occupy 98 l at a pressure of 2.8 atmospheres and a temperature of 292 k?

Furkat [3]

From the ideal gas equation, we know that PV = nRT
where, P = pressure, V = volume occupied, n = number of moles of gas, R = universal gas constant=0.082L atm mol-1 K-1 and T = temperature.
Given: P = 2.8 atm, V = 98 l and T = 292 k.
Therefore n = $\frac{PV}{RT}$ = $\frac{2.8 X 98}{0.082 X 292}$ = 11.46

6 0

3 years ago

If a decrease in temperature accompanies a reaction,what occurred? energy was destroyed energy was restored energy was created e

forsale [732]

I think the correct answer from the choices listed above would be the last option. If a decrease in temperature accompanies a reaction, then energy was absorbed which means that the reaction is endothermic. Hope this answers the question. Have a nice day.

7 0

3 years ago

Read 2 more answers

Only a small fraction of a weak acid ionizes in aqueous solution. What is the percent ionization of a 0.100-M solution of acetic

Mademuasel [1]

Answer:

1.33%

Explanation:

In an aqueous solution, a weak acid such as acetic acid, will be in equilibrium with its conjugate base, acetate ion, thus:

CH₃CO₂H(aq) + H₂O(l) ⇌ H₃O⁺(aq) + CH₃CO₂⁻(aq )

Where dissociation constant, ka, is defined as the ratio of concentrations of products and reactants:

Ka = 1.8x10⁻⁵ = [H₃O⁺] [CH₃CO₂⁻] / [CH₃CO₂H]

H₂O is not taken into account in the equilibrium because is a pure liquid

When a solution of acetic acid becomes to equilibrium, the original concentration of the acid decreases producing more H₃O⁺ and CH₃CO₂⁻.

The concentrations at equilibrium when a 0.100M solution of acetic acid reaches this state, is:

[CH₃CO₂H] = 0.100M - X

[H₃O⁺] = X

[CH₃CO₂⁻] = X

Where X is reaction coordinate.

Replacing in Ka expression:

1.8x10⁻⁵ = [H₃O⁺] [CH₃CO₂⁻] / [CH₃CO₂H]

1.8x10⁻⁵ = [X] [X] / [0.100M - X]

1.8x10⁻⁶ - 1.8x10⁻⁵X = X²

1.8x10⁻⁶ - 1.8x10⁻⁵X - X² = 0

Solving for X:

X = -0.00135 → False solution. There is no negative concentrations.

X = 0.00133 → Right solution.

That means concentration of acetate ion is:

[CH₃CO₂⁻] = 0.00133M.

Now, percent ionization is defined as 100 times the ratio between weak acid that is ionizated, [CH₃CO₂⁻] = 0.00133M, per initial concentration of the acid, [CH₃CO₂H] = 0.100M. Replacing:

% Ionization = 0.00133M / 0.100M × 100 =

4 0

3 years ago