SORRY :(
4 DISCUSSIN goiit ques here.... but over ther none get solved and no Expert replies!!!
QUE 1
Lattice (III): A atoms and B atoms crystallises as: A atoms occupying the corners whereas B atoms are occupying all the edge centre positions.
What is closest distance between two B atoms? (edge length of the unit cell of lattice III = a)
optns are a/2, a/√2, a/2√2, 2a.... [MA ANS 1 , THEIR ANS 2 ]
QUE 2
Lattice (I): A compound of Cd, Sn and P is used in the fabrication of some semiconductors. It crystallizes with Cd occupying one quarter of the tetrahedral holes and Sn occupying one quarter of tetrahedral holes in the closed packed array of P ions.
What is the molecular formula of the compound as in lattice (I)?
MY anS = CdSnP2
THEIRS = Cd2Sn2P4
1yah.......... we hav got the ratio rite 4 sure.....
now the questn is wat is da reason Bhind it being twiced sumthing like empirical formula n molecular formula...........
nething to do with charge neutrality and oxidation states ????? { jus a guess}
1357One doubt
what is the molecular formula of salt
NaCl or Na4Cl4
3hey...
they have asked the 'molecular formula'...so u need to take the total no. of atoms actually present in the lattice, not merely their ratio...
so its b, not a...
1priyam,
both the options wer a part of the question........
quite obviously then only my ans cud hav bn one of em and the other as the correct answer as per them
21wats da diff b/w the 2 options?????
i've never seen a que wer both empirical formula and molcular formula r a part of the options
has ne1????
62Q1)
Distance between the closest atoms will be such that they lie on hypotenuse of a right angled triangle with sides a/2
thus the answer is a/2x√2
=a/√2
1the thing is not complete but gave only the general picture.
see to find the molecular formula . just see the number of atoms inside it.
there are 8 corners which have 1/8 of an atom.
then 12 1/4 atoms ,thus there should be 4 atoms on the whole . so your option seems alright to me. I dunno . might've done something wrogn.
1well , see here the 3-D structure will be as shown by anurag , which is the top view ,here is the side view.
62Magic Math.. I am not sure either.. Not that I am an expert at this topic.. but i think your answer and their answer are equivalent with the given data...
neone who can clarify on this one?
1Pl. help out in the cadmium sulphide phosphorus question!!!!!
1oh yaaaaaa!!!
i had found out the closest dist bw an A and B atoms....
wat abt the 2nd questn....
i did it by takin ratio of tot no. of atoms per unit cell and tickd optn a without reading further......
but Cd2Sn2P4 also has the same ratio..... so how 2 distinguish bw the two???????
