Question

10. Which value would be required to estimate the lattice energy for the hypothetical ionic compound MgH?
A. the electron affinity of hydrogen
B. the first ionization energy of hydrogen
C. the magnesium-hydrogen bond energy
D. the standard enthalpy change of formation of MgH

I think its C .because if we know the bond energy between them we can calculate lattice energy I guess :/ not sure

Answer 1

@JFraser @shrutipande9 @atlas

Answer 2

@amistre64

Answer 3

@Luigi0210

Answer 4

@aaronq Can u help me please ...

Answer 5

the bond energy might be useful, but i'd rather use the overall enthalpy of formation

Answer 6

ok. but the answer key show A as correct ..:/

Answer 7

ok, since the H atom has to grab onto one of the electrons that the Mg will donate. I'm not really good with lattices

Answer 8

it mean you're not sure ???

Answer 9

not really, no

Answer 10

ok..ty for ur concern :)

Answer 11

yw

Answer 12

btw, asking big questions in chat really annoys people, that's why we have the topics

Answer 13

ops sorry :)

Answer 14

I think the formula would first have to be \(MgH_2\) where H are hydrides... also, there is the borne-lande equation to estimate the lattice energy of a crystal. So you might wanna look at that. I'm not sure how the e affinity of hydrogen would let you calculate that.

Answer 15

I also don't know y its is A ...that's y I asked for help ..anyways ty :)

Answer 16

@sarah786 : sry didn't see your message earlier
and I don't think A is the right answer..............it gotta be D
Lattice energy is the measure of the strength of the bond in the ionic compund which is completely described by enthalpy of formation

Answer 17

I know but its for MgH2 not for MgH ...@JFraser @aaronq @atlas Can y'all check this Paper please . Question 9 I asked .... https://thol.sunway.edu.my/examdbase/alv/chem/p3/chem_p3_j98.pdf

Is this question is wrong ????

Answer 18

@JFraser

Answer 19

@sarah786 : Remember it is a HYPOTHETICAL compound

Answer 20

whether it's hypothetical or not, the electron affinity of each hydrogen will probably work. the Mg will give away 2 electrons, but each H can only accept one. It's not unreasonable to just double the electron affinity of hydrogen to get the lattice energy

Answer 21

ok then Tell me d right one ? C or D ?

Answer 22

like i said before, i don't know lattice energy well enough to answer this with certainty

Answer 23

@sarah786 : I was just checking the question paper and I saw that you have mentioned the last option wrong (the standard enthalpy change of formation of MgH2 and NOT MgH ) - so D is ruled out of question

Answer 24

ops really sorry . that's why I showed you paper now which one is correct ??

Answer 25

I believe its C then

Answer 26

its A @atlas @JFraser @aaronq

My for ionic bond strength, lattice energy is used and strength of H anion is judged by its E.A .As Mg metal so that act as cation .so correct answer is A and why it is not C because Bond energy is a general term used for strength of covalent bond

Answer 27

makes sense, since the Mg will act as the cation, the H must accept an electron, which is a reflection of EA, not IE. I still think the question is a little vague, but now it seems solved.

Answer 28

:)