1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Advocard [28]
3 years ago
12

Estimate the coordination number for the cations in each of these ceramic oxides and also the coordination numbers of the oxygen

anions: Al2O3, B2O3, CaO, MgO, TiO2, LaAlO3, Mg2SiO4, and NiCo2O4.
Chemistry
1 answer:
Juli2301 [7.4K]3 years ago
5 0

Answer:

CN cation, anion ] respectively are thus [6,4] , [2,3] ,[6,6] , [6,6] , [6,3] , [12,6,2] , [6], [6].

Explanation:

The coordination number CN is the number of ligand atoms bonded (coordinate bonds) directly to the central of the metal ion. It is not the same as the oxidation state of the metal ion or complex.

Coordination number – the number of anions surrounding the cation.

In solving for CN we need to understand Pauling's rules.

According to Linus Pauling, 1932

“Pauling’s rules” for crystal structures, makes assumptions for ionic bonding. It states that ionic structure is understood using electrostatic rules of attraction and repulsion.

Cations and anions surround each other to neutralize charge – and these one can rationalize crystal structure with coordination number.

Ratio of cationic/anionic radius

• The structure of D-Al2O3 results in coordination number of 6 and 4 for cation and anion respectively.

• The average oxygen coordination number in v-B2O3 is equal to the average cation coordination number × cation/anion ratio (2/3).

• Co-ordination number of Ca2+ ion is =6;

In CaO crystal, Ca2+ is a cation and O2- is an anion. Cationic (Ca2+) has radius 100 pm and anionic (O2-) has radius  145 pm.

Ratio of cationic/anionic radius is:

r⁺/r⁻ = 100 / 145

r⁺/r⁻ = 0.69

CaO will form FCC lattice.

Coordination number in FCC lattice is 6. Therefore CN of Ca2+ = 6.

For MgO:

r Mg2+/ r O2- = 86pm / 126 pm =0.683

The cordination number for the cation is 6. MgO with ions Mg+2 and O-2 will have a AX type stochiometry exhibiting the

crystal structure of sodium chloride.

For TiO2:

The CN of the titanium (IV) cation is 6, which is twice the CN of the oxide anion, which is 3.

This fits with the formula unit of TiO2, since there are twice as many O2− ions as Ti4+ ions.

Consequently the crystal structure of all ionic compounds reflects the formula unit.

For LaAlO3 a Cubic perovskites (ABX3)

In perovskite structures, B cations are coordinated by six X anions, while A

cations present CN = 12 (also coordinated by X anions). The X anions have CN = 2, being

coordinated by two A cations, since the distance A-O is about 40% larger than the B-O

bond distance. The correct ionic radii (rA, rB, rX), taken from one of Shannon’s work.

rA = 1.36 pm

rB = 0.535 pm

rX = 1.35 pm

Forsterite Mg2SiO4

We have mixed sites of Si4+ in tetrahedral site, Mg2+ in octahedral site, O atoms anions .

They all forms octahedral chains/strips. The CN is estimated to (6) octahedral, with an average ratio 0.414

Nickel Cobaltite Ni(Co2O4)3

bidentate ligand includes the Oxalate, three oxalate ligands form six-coordinate bonds around the Ni2+ ion.

Co-ordinate number of Nickel in [Ni(C2​O4​)3​] 4− is 3×2=6.

You might be interested in
What volume of stock solution and water must you add to prepare 36.25ml of a 1.25M solution
Serjik [45]

Given :

Number of moles , n = 36.25 mol .

Molarity , M = 1.25 M .

To Find :

The volume of water required .

Solution :

Moarity is given by :

M=\dfrac{n}{V}

So , V=\dfrac{n}{M}

Here , n is number of moles and M is molarity .

Putting all values in above equation , we get :

V=\dfrac{36.25}{1.25}\\\\V=29\ L

Therefore , volume of water required is 29 L .

5 0
3 years ago
How many ammonium ions and how many sulfate ions are present in an 0.250 mol sample of (nh42so4?
Nastasia [14]
Thw answer is PHj78 JJ CP30 R2D2
7 0
3 years ago
Copper is an example of a(n)
expeople1 [14]

copper is not a stone, copper is not a consumption resource, and copper is not renewable, that means that :

d. nonrenewable resource

Explanation:

A nonrenewable source is a source of economic value that cannot be immediately displaced by natural means on a level equal to its destruction. Most fossil fuels, such as oil, natural gas, and coal are estimated nonrenewable resources in that their use is not sustainable because their production takes billions of years.

7 0
3 years ago
Read 2 more answers
You have collected a tissue specimen that you would like to preserve by freeze drying. To ensure the integrity of the specimen,
Reika [66]

Answer:

The maximum pressure is 612.2 Pa

Explanation:

The pressure of the ice (P1) = 624 Pa

The temperature of the ice = 273.16 K

The maximum temperature the specimen = - 5 oC

                                                                     = -5 + 273 = 268K

The maximum Pressure the freeze drying can be will be (P2) = ?

Using Pressure law, which shows the relationship between pressure and temperature.

                        P1 / T1 = P2 / T2

                       P2 T1 = P1 T2

                       P2 = P1 T2 / T1

                       P2 = 624 × 268 / 273.16

                       P2 = 612.2 Pa

The maximum pressure at which drying can be carried out is 612.2 Pa

Check the attached document more explanation.   jjjjggggg

5 0
3 years ago
In the process of electrolysis, current can flow through a liquid because A. water molecules become negatively charged. B. hydro
Liula [17]
<span>B. Hydrogen is electrically neutralized in the solution. Hydrogen is a chemical element with symbol H and atomic number 1. With a standard atomic weight of circa 1.008, hydrogen is the lightest element on the periodic table.</span>
4 0
3 years ago
Read 2 more answers
Other questions:
  • It kinda healing it is kinda doing well
    7·1 answer
  • Blue light has a frequency of 6.98 • 10^14 Hertz. Calculate the wavelength of blue light in nanometers.
    9·1 answer
  • 2. Rank the boiling points of methane, methanol, and methanal from lowest to highest. Explain your ranking. (6 points) 3. The lo
    5·1 answer
  • A 100-watt light bulb radiates energy at a rate of 100 J/s. (The watt, a unit of power or energy over time, is defined as 1 J/s.
    11·1 answer
  • A gas that exerts a pressure of 2.15 atm in a container with a volume of 0.0900 L will exert a pressure of ___ atm when transfer
    15·1 answer
  • How many moles are in 7.8g of CaO?
    15·1 answer
  • A solution is prepared by dissolving 51 g of salt in 340 g of
    10·1 answer
  • We'll need a new what <br> to support the cleaner energy world of the future.
    10·1 answer
  • What form when moisture evaporates into the air and then cools?
    5·2 answers
  • Consider each possible structure of carbon dioxide, c o 2. Determine whether the structure is correct and justify your decision.
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!