All categories

3 years ago

The following compounds have similar molecular weights. which would be expected to have the lowest boiling point?

Chemistry

1 answer:

Oksanka [162]3 years ago

3 0

Answer:

Methane (B) is expected to have the lowest boiling point.

Explanation:

There are to ways of solving this problem.

The first one is considering the physical state of matter that this compounds are found in normal conditions (room temperature):

(A) calcium carbonate - solid

(B) methane - gas

(D) dimethyl ether (CH₃OCH₃) - liquid

Methane is the only gas, therefore it has the lowest boiling point.

The second one is considering the molecular interactions between the molecules of each compound:

(A) calcium carbonate - it is a salt - eletrostatic interactions between ions - very strong

(B) methane - non-polar molecule - induced dipole - very weak

(D) dimethyl ether (CH₃OCH₃) - liquid - dipole-dipole - relatively strong

The intermolecular interactions in methane are the weakest, therefore it has the lowest boiling point.

You might be interested in

What is the difference between docosahexaenoate (DHA) and 19,20-dihydroxydocosapentaenoate (19,20-DHDP)? Only DHA is a polyunsat

andrew11 [14]

Answer:

Explanation:

The correct answer is 19, 20 DHDP is more polar than DHA. This is as a result of the presence of two hydroxyl groups.

4 0

3 years ago

Which of the following elements is most likely to form an ion that will then form an ionic bond with an ion of a Group 1A elemen

solniwko [45]

Group 1A (the alkali metals) almost always form cations (positive ions). They'd need anions (negative ions) to ionic bond with. Beryllium (Be) is group 1A already and forms Be+ cation. Bromine is a halogen, and forms Br-, an anion. Platinum is a metal, and usually won't ionic bond with anything. Francium is rare and highly radioactive, plus it so happens to be group 1A as well. Only bromine can form the anion that the group 1A cations need.

3 0

3 years ago

Using the following standard reduction potentials, Fe3+(aq) + e- → Fe2+(aq) E° = +0.77 V Ni2+(aq) + 2 e- → Ni(s) E° = -0.23 V ca

lina2011 [118]

Answer: The above reaction is non-spontaneous.

Explanation:

For the given chemical reaction:

$Ni^{2+}(aq.)+2Fe^{2+}(aq.)\rightarrow 2Fe^{3+}(aq.)+Ni(s)$

Here, nickel is getting reduced because it is gaining electrons and iron is getting oxidized because it is loosing electrons.

We know that:

$E^o_{(Fe^{3+}/Fe^{2+})}=0.77V\\E^o_{(Ni^{2+}/Ni)}=-0.23V$

Substance getting oxidized always act as anode and the one getting reduced always act as cathode.

To calculate the $E^o_{cell}$ of the reaction, we use the equation:

$E^o_{cell}=E^o_{cathode}-E^o_{anode}$

$E^o_{cell}=-0.23-0.77=-1.0V$

Relationship between standard Gibbs free energy and standard electrode potential follows:

$\Delta G^o=-nFE^o_{cell}$

As, the standard electrode potential of the cell is coming out to be negative for the above cell. Thus, the standard Gibbs free energy change of the reaction will become positive making the reaction non-spontaneous.

Hence, the above reaction is non-spontaneous.

3 0

3 years ago

What is the hybridization of the carbon atoms in 1,3-butadiene, h2c=ch-ch=ch2?

Natalija [7]

The main formula is as follow is explained in the attached file (please look at the examples)

the 1,3- butadiene is h2c=ch-ch=ch2, so we have

sp² sp² sp² sp²
h2c = ch - ch = ch2

the hybridization of the carbon atoms is sp² : trigonal planar

4 0

3 years ago

Primary alcohol oxidation products

Yuliya22 [10]

write an equation to represent the oxidation of an alcohol.

identify the reagents that may be used to oxidize a given alcohol.

identify the specific reagent that is used to oxidize primary alcohols to aldehydes rather than to carboxylic acids.

identify the product formed from the oxidation of a given alcohol with a specified oxidizing agent.

identify the alcohol needed to prepare a given aldehyde, ketone or carboxylic acid by simple oxidation.

write a mechanism for the oxidation of an alcohol using a chromium(VI) reagent.

The reading mentions that pyridinium chlorochromate (PCC) is a milder version of chromic acid that is suitable for converting a primary alcohol into an aldehyde without oxidizing it all the way to a carboxylic acid. This reagent is being replaced in laboratories by Dess‑Martin periodinane (DMP), which has several practical advantages over PCC, such as producing higher yields and requiring less rigorous reaction conditions. DMP is named after Daniel Dess and James Martin, who developed it in 1983.

This page looks at the oxidation of alcohols using acidified sodium or potassium dichromate(VI) solution. This reaction is used to make aldehydes, ketones and carboxylic acids, and as a way of distinguishing between primary, secondary and tertiary alcohols.

Oxidizing the different types of alcohols

The oxidizing agent used in these reactions is normally a solution of sodium or potassium dichromate(VI) acidified with dilute sulfuric acid. If oxidation occurs, the orange solution containing the dichromate(VI) ions is reduced to a green solution containing chromium(III) ions. The electron-half-equation for this reaction is

Cr2O2−7+14H++6e−→2Cr3++7H2O

3 0

3 years ago