The electronegativities of the -C≡CH and -C≡N groups are the same, but the dipole moments of...

The electronegativities of the -C≡CH and -C≡N groups are the same, but the dipole moments of the CH3C≡CH and the CH3C≡N are 0.78 D and 3.92 D, respectively. Explain why the dipole moments are so different.

Solutions

Expert Solution

Electrons are shared by atoms while forming a bond. If the electrons are shared unequally, then it creats small equal and opposite charge difference on the atoms. Often, when two atoms with different electronegativity share the electrons unequally, they form this small charge difference and due to this dipole moment is created. Which is a result of more electronegative atom pulling the shared electrons towards itself.

In terminal alkyne C triple bond C, the electronegativity difference in the two carbons is not much. Whereas, in C triple bond N (nitrile group) the electronegativity difference is large and so it shares the electrons unequally. This creats difference is small charges on C and N. Additionally, nitrogen has loan pair of electrons which adds to the magnitude of dipolemoment in nitrile group. So the dipole moment in nitrile is more as compared to alkyne C triple bond C.

Electronegativity of alkyne overall is same as nitrile because the positive inductive effect of nitrogen is doesnot pass much after the first carbon.

queen_honey_blossom answered 2 years ago

Next > < Previous

Related Solutions

The dipole moments decrease across the series PH3 > AsH3 > SbH3 > BiH3. Why do...

The dipole moments decrease across the series PH3 > AsH3 > SbH3 > BiH3. Why do the boiling points increase? Check all that apply. The electron clouds of the molecules become smaller along the series. The electron clouds of the molecules become larger along the series. The smaller numbers of electrons are more polarizable, leading to greater dispersion forces. The larger numbers of electrons are more polarizable, leading to greater dispersion forces.

Estimate the dipole moments of all five possible HX compunds, where X is a halogen, using...

Estimate the dipole moments of all five possible HX compunds, where X is a halogen, using only the Pauling electronegativities and showing your answers in both Coulomb-meters and Debye. What is responsible for the trend in polarities of these bonds that your calculations predict? (i.e. what causes the differences in the halogen electronegativities?) Follow-up question: How does this trend differ from that of van der waals interactions involving the halogens?

Why does krypton form crystals at sufficiently low temperatures despite having no permanent dipole moments?

The strongest intermolecular force that exists in the following molecule is? o=c=o a. LDF's B. dipole-dipole...

The strongest intermolecular force that exists in the following molecule is? o=c=o a. LDF's B. dipole-dipole C. Hydrogen Bonding D. Covalent bonding

your next assignment is about teams. teams are the same as groups, except that groups are...

your next assignment is about teams. teams are the same as groups, except that groups are informal, and teams are formal, groups elect their own leaders, and team leaders are assigned by the management of the company, and teams are specific to the company's tasks. examples of teams are quality control teams, and project teams. there are other examples of teams, and that is your first team assignment: find at least 5 examples of teams used by companies in the...

Explain the following: True/False: Two different compounds with the same functional groups will have the same...

Explain the following: True/False: Two different compounds with the same functional groups will have the same IR spectra? True/False: IR absorption frequency between functional groups varies greatly? The mass of the atoms in a bond is directly or inversely proportional to the vibrational frequency? Will the conjugation of pi bonds increase or decrease the frequency of the peak?

Draw the skeletal structure CH3CH (C (CH3)3)CH (CH2CH2CH2CH3)CH(CH3)2 and name it. also can you do a...

Draw the skeletal structure CH3CH (C (CH3)3)CH (CH2CH2CH2CH3)CH(CH3)2 and name it. also can you do a step by step way to break the skeletal structure to make it easier to draw it.

Write a program in C or C++ that takes a number series of size n (n...

Write a program in C or C++ that takes a number series of size n (n integers) as input from the user, push all the numbers to the stack, and reverse the stack using recursion. Please note that this is not simply popping and printing the numbers, but the program should manipulate the stack to have the numbers stored in reverse order. In addition to the provided header file, the students can use the following function to print the content...

n insurance portfolio consists of two homogeneous groups of clients; N i, (i = 1 ,...

n insurance portfolio consists of two homogeneous groups of clients; N i, (i = 1 , 2) denotes the number of claims occurred in the ith group in a fixed time period. Assume that the r.v.'s N 1, N 2 are independent and have Poisson distributions, with expected values 200 and 300, respectively. The amount of an individual claim in the first group is a r.v. equal to either 10 or 20 with respective probabilities 0.3 and 0.7, while the...

Two vessels contain the same number N of molecules of the same perfect gas. Initially the...

Two vessels contain the same number N of molecules of the same perfect gas. Initially the two vessels are isolated from each other, the gases being at the same temperature T but at different pressures P1 and P2. The partition separating the two gases is removed. Find the change of entropy of the system when equilibrium has been re-established, in terms of initial pressures P1 and P2. Show that this entropy change is non-negative.

Subjects