Chemistry, 03.03.2020 05:03 Cassandoo

Use molecular orbital theory to predict whether or not each of the following molecules or ions should exist in a relatively stable form. Drag the appropriate items to their respective bins. C2 2+ Be2 2+ Li2 Li2 2

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The ions or molecule C2 2+ Be2 2+ Li2 exists in stable form but Li2 2 does not exist in stable form when using molecular orbital theory to predict their stability.

The production of molecular orbitals arises by combining atomic orbitals in a linear array. Based on the electronic configuration of molecular orbitals, the stability of molecules or ions can be determined by calculating the bond order for each molecule.

The bond order can be expressed as: $\mathbf{= \dfrac{1}{2} \Big[no \ of \ electrons \ in \ B.O - No \ of \ electrons \ in \ Anti \ B.O \Big]}$

where:

B.O = Bonding Orbital

For C₂²⁺:

The carbon atom has an electronic configuration of 1s²2s²2p². It has 12 electrons. For the formation of C₂ from C₂²⁺, there is the removal of 2 electrons.

As such, C₂²⁺ has 10 electrons.

Now, the electronic configuration for the molecular orbital for C₂²⁺ can be written as:

$\mathbf{ \sigma_{1s}^2 < \sigma _{1s}^{*2} < \sigma _{2s}^{2}< \sigma _{2s}^{*2} < \pi _{2py}^{1}=\pi _{2pz}^{1} < \pi _{2px}^{0} < \pi _{2py}^{*0}= \pi _{2pz}^{0} < \pi _{2px}^{0} }$

where;

the orbitals with (*) = antibonding orbitals the orbitals without (*) = bonding orbitals

Bond Order $= \mathbf{\dfrac{1}{2} (6-4)}$

$= \mathbf{\dfrac{1}{2} (2)}$

= 1

Thus, since Bond order = 1, the C₂²⁺ ion exist in a stable form

For Be₂²⁺ is a beryllium atom with a configuration is 1s² 2s². It has 8 electrons, for the formation of Be₂ from Be₂²⁺, there is the removal of 2 electrons. As such, Be₂²⁺ has 6 electrons, the electronic configuration for the molecular orbital can be expressed as:

$\mathbf{ \sigma_{1s}^2 < \sigma _{1s}^{*2} < \sigma _{2s}^{2}< \sigma _{2s}^{*0} < \pi _{2py}^{0}=\pi _{2pz}^{0} < \pi _{2px}^{0} < \pi _{2py}^{*0}= \pi _{2pz}^{0} < \pi _{2px}^{0} }$

Bond Order $= \mathbf{\dfrac{1}{2} (4-2)}$

$= \mathbf{\dfrac{1}{2} (2)}$

= 1

Thus, since Bond order = 1, the Be₂²⁺ ion exist in a stable form

Lithium Li₂ has an atomic number 3 with an electronic configuration 1s² 2s¹. Thus, it comprises 6 electrons. The electronic configuration of its molecular orbital is expressed as;

$\mathbf{ \sigma_{1s}^2 < \sigma _{1s}^{*2} < \sigma _{2s}^{2}< \sigma _{2s}^{*0} < \pi _{2py}^{0}=\pi _{2pz}^{0} < \pi _{2px}^{0} < \pi _{2py}^{*0}= \pi _{2pz}^{*0} < \pi _{2px}^{*0} }$

Bond Order $= \mathbf{\dfrac{1}{2} (4-2)}$

$= \mathbf{\dfrac{1}{2} (2)}$

= 1

Thus, since Bond order = 1, the Li₂ ion exists in a stable form

In Li₂²⁻, the number of electrons for its formation is 8; Since it needs 2 more electrons to its initial 6 electrons in Li₂. so, the electronic configuration of its molecular orbital can be expressed as;

$\mathbf{ \sigma_{1s}^2 < \sigma _{1s}^{*2} < \sigma _{2s}^{2}< \sigma _{2s}^{*2} < \pi _{2py}^{0}=\pi _{2pz}^{0} < \pi _{2px}^{0} < \pi _{2py}^{*0}= \pi _{2pz}^{*0} < \pi _{2px}^{*0} }$

Bond Order $= \mathbf{\dfrac{1}{2} (4-4)}$

$= \mathbf{\dfrac{1}{2} (0)}$

= 0

Thus, since Bond order = 0, the Li₂²⁻ ion does not exist in a stable form

Learn more about molecular orbital theory here:

link

Use molecular orbital theory to predict whether or not each of the following molecules or ions shoul

Answer from: Woodsydal2390

C2 2+ stable and should exist

Be2 2+ stable and should exit

Li2 stable and should exit

Li2 2- unstable and doesn't exist

Explanation:

The first step in predicting the stability of a specie is knowing its molecular orbital configuration and bond order. If the Specie has a bond order of one or more, it is expected to exist in a stable form. The image attached shows the bond order and molecular orbital configuration of all the species mentioned in the question. This will aid you in understanding the stability of each specie.

Answer from: Quest

the movement of aircraft through clouds can even cause lightning strikes. a single lightning event is a "flash", which is a complex, multi-stage explosively ejected.

explanation:

and the person below goggled it.

mark as brainliest

Answer from: Quest

but know think of it in terms of bond breaking and bond making.

h–h + h–h + o=o ==> h–o–h + h–o–h

as you can see from the diagram, theoretically, more energy is released by forming water, than was absorbed in breaking up the original hydrogen and oxygen molecules.

the energy level of the fuel + oxygen is higher than that of water.

therefore the fuel + oxygen mixture has the potential to release potential chemical energy as heat energy or, crucially, electrical energy, if the reaction can be made to go via oxidation and reduction reactions involving electron transfer.

see this page for more details of the full bond energy calculations

a fuel cell is a device to make electricity that functions like an electrical cell or battery that you supply with a fuel (liquid or gas) and an oxidant (oxidising agent, usually oxygen gas) which react together in a redox reaction (oxidation + reduction) to release energy as a flow of electrons i.e. an electrical current capable of doing useful work.

the oxidation of the fuel and the reduction of the oxidant reactions take place on electrodes (see diagram on right, all fully explained further down the page).

fuel cells essentially a device to release the chemical potential energy of combustible fuels as electrical energy at a much lower temperature and without the flame!

so, the idea of a hydrogen–oxygen fuel cell is to release the energy from hydrogen reacting with oxygen, not as heat as in normal combustion in air, but as useful electrical energy i.e. a practical electricity supply.

hydrogen-oxygen fuel cells are much efficient than conventional power stations or batteries (e.g. zinc-carbon) because the electrical energy is directly generated from the chemical reaction between the oxidant and the fuel - there are no complications with boilers, turbines and generators.

in fossil fuel power stations, motor vehicles, coal/gas fires etc. quite a percentage of energy is lost as waste heat.

with a fuel cell there are fewer stages in producing the useful energy, so there is less opportunity to lose potentially useful energy e.g. waste heat, friction from moving parts etc.

a hydrogen–oxygen fuel cell is a non–polluting clean fuel since the only combustion product is water.

fuel cells do not produce pollutants like carbon monoxide, sulfur dioxide and nitrogen oxides - gases you get from fossil fuel combustion in power stations or burnt road vehicles..

cars powered by fuel cells would be quite an environmental advantage in cities, where electric cars are already beginning to be significantly used in developed countries.

fuel cells could replace larger batteries which are not easily recycled and contain highly toxic metal compounds.

it would be an ideal fuel on this basis e.g. for motor vehicles, but that's not the only factor to consider!

it would be ideal if the hydrogen fuel could be manufactured by electrolysis of water e.g. using solar cells.

hydrogen can be used to power fuel cells.

it all sounds wonderful but, still technological problems to solve for large scale manufacture and distribution of 'clean' hydrogen gas or use in generating electricity and its rather an inflammable explosive gas!

explanation:

fuel cells e.g. the hydrogen-oxygen fuel electrical cell

fuel cells have to be supplied by an external source of fuel (e.g. hydrogen) and an oxidant e.g. oxygen or air.

the hydrogen or any other fuel is oxidised electrochemically inside the fuel cell to produce a potential difference i.e. a voltage capable of producing a working current.

the overall chemical reaction in a hydrogen fuel electrochemical cell involves the oxidation of hydrogen by oxygen to produce only water.

hydrogen fuel cells offer an alternative to rechargeable cells and batteries.

a fuel cell will produce a potential difference ('voltage') and a workable electric current until one of the reactants is used up.

hydrogen gas can be used as fuel.

it burns with a pale blue flame in air reacting with oxygen to be oxidised to form water.

hydrogen + oxygen ==> water

2h2(g) + o2(g) ==> 2h2o(l)