Chemistry: Post your doubts here!

[MarcoReus]

Is there a difference between square bipyramidal and octahedral? Because Q2(e) of the S11 P22 MS (link below) states the SF6 molecule to have the octahedral shape (not both).
http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s11_ms_22.pdf

 

[Awesome12]

Is there a difference between square bipyramidal and octahedral? Because Q2(e) of the S11 P22 MS (link below) states the SF6 molecule to have the octahedral shape (not both).
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s11_ms_22.pdf

Our sir made us write that SF6 has the octahedral shape. I should you should check what your sir made you write. In addition to that, you should follow the marking scheme.

 

[NinjaInPyjamas]

Is there a difference between square bipyramidal and octahedral? Because Q2(e) of the S11 P22 MS (link below) states the SF6 molecule to have the octahedral shape (not both).
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s11_ms_22.pdf

It's the same thing, but the term octahedral is preferred.

 

[MarcoReus]

It's the same thing, but the term octahedral is preferred.

Phew.

 

[Riding hood]

Can anyone please advise on how to solve calculations in titration questions in chemistry practical, im very bad at it , dont understand a simgle question :/

 

[Snowysangel]

For which reactions will writing "reflux" not be appropriate? Are there marks for writing it as a condition for other organic reactions??

 

[Snowysangel]

Re: All Chemistry help here!! Stuck somewhere? Ask here!

explain trend of solubility of group 2 sulphates.....well in anser to this.....we have to write that hydration enthalpy decrese faster than lattice bt i dont undrstnd how

The equation for the enthalpy of solution is. E= hydration energy - lattice energy so if the value of hydration energy is greater than the lattice energy then the enthalpy of solution will be positive. As a general rule, the more positive the enthalpy of solution is, the higher is the solubility. The hydration energy depends on the cations, so the difference in their size is relevant to the change in energy, while for lattice energy, neutral molecules are formed and since the sizes of the cations are negligible compared to the sulfate ion, the size of the molecule remains roughly the same as we decend the group so the lattice energy doesn't change that much, but as the the size of the cation increases down the group l, the hydration energy decreases significantly. Since the decrease in hydration energy is greater than the decrease in LE, the enthalpy of soliton is less positive and the solubility deceases

 

[MarcoReus]

If we remove three electrons from 3 half-filled orbitals from the same p subshell, why is there a small increase in ionization energy in each of them?

 

[MarcoReus]

Like, why is there an increase in 3rd to 4th I.E. and 4th to 5th I.E?

 

[Dark Destination]

If we remove three electrons from 3 half-filled orbitals from the same p subshell, why is there a small increase in ionization energy in each of them?

Because they are at different energy levels?

 

[Awesome12]

Like, why is there an increase in 3rd to 4th I.E. and 4th to 5th I.E?

After the removal of an electron, the already present electrons tend to get closer to each other. Thus it is becomes harder to remove another electron.
Such questions won't really come. They would rather prefer to ask simplistic statements, like why is there an abrupt increase in the ionization energy between the 2nd and 3rd I.E




Another possible explanation. In Magnesium, the p sub-shell is complete with THREE PAIRS. The first electron in the FIRST PAIR is removed at the cost of residual repulsion. This makes removing the electron easier. Then electrons get closer to each other. The other electron in the FIRST PAIR is more difficult to remove...

 

[Awesome12]

Because they are at different energy levels?

They are degenerate orbitals ; orbitals on the same energy level.

 

[Dark Destination]

Another possible explanation. In Magnesium, the p sub-shell is complete with THREE PAIRS. The first electron in the FIRST PAIR is removed at the cost of residual repulsion. This makes removing the electron easier. Then electrons get closer to each other. The other electron in the FIRST PAIR is more difficult to remove...

What?

Aren't electrons first removed from 3s in magnesium?

 

[Awesome12]

What?

Aren't electrons first removed from 3s in magnesium?

He asked about the difference in I.E between the 3rd and 4 th and 4th and 5th.

 

[MarcoReus]

After the removal of an electron, the already present electrons tend to get closer to each other. Thus it is becomes harder to remove another electron.
Such questions won't really come. They would rather prefer to ask simplistic statements, like why is there an abrupt increase in the ionization energy between the 2nd and 3rd I.E




Another possible explanation. In Magnesium, the p sub-shell is complete with THREE PAIRS. The first electron in the FIRST PAIR is removed at the cost of residual repulsion. This makes removing the electron easier. Then electrons get closer to each other. The other electron in the FIRST PAIR is more difficult to remove...

So you are saying repulsions decrease and that's the reason?
My theory is (once I thought about it) that when one electron leaves, the charge goes to +1 and thus it's the same amount of protons attracting one less electron so the bond between the nucleus and the remaining electrons gets stronger thus rising the I.E.

And Dark Destination, read the question clearly.

 

[Awesome12]

So you are saying repulsions decrease and that's the reason?
My theory is (once I thought about it) that when one electron leaves, the charge goes to +1 and thus it's the same amount of protons attracting one less electron so the bond between the nucleus and the remaining electrons gets stronger thus rising the I.E.

And Dark Destination, read the question clearly.

Would you care to read it again?

 

[MarcoReus]

Would you care to read it again?

I'll just assume you wrote what I wrote in your version of English.

 

[Dark Destination]

He asked about the difference in I.E between the 3rd and 4 th and 4th and 5th.

Okay, Chemistry master.

 

[Dark Destination]

HCL doesn't have Hydrogen bonding? Why? :/

 

[Dark Destination]

What is the difference between Permanent-Dipole attraction and Hydrogen bonding?