Question

CaO and NaCl have the same crystal structure and approximately the same ionic radii. If U is the lattice energy of NaCl, the approximate lattice energy of CaO is

Solution

Correct option is

4U

Lattice energy, 

Since, interionic distances in CaO and NaCl are similar, (larger cation has smaller anion and vice versa) r is almost the same. Therefore, lattice energy depends only on charge.  

Since, the magnitude of charge on  ions is same ie, unity and that on  ions is 2 each, therefore, the lattice energy of CaO is four times the lattice energy of NaCl, ie, 4U.  

SIMILAR QUESTIONS

Q1

The correct sequence of decreasing dipole moments of the following molecules will be

Q2

Which of the following species is not paramagnetic?

Q3

Which of the following has maximum dipole moment?

Q4

The correct order of decreasing bond length for , NO and NO+ is

Q5

Among the species:  which has the weakest C – O bond?

Q6

Which bond angle  would result in the maximum dipole moment for the triatomic molecule yxy?

Q7

The dipole moment of HBr is  and interatomic spacing is  The %ionic character of HBr is

Q8

In a polar molecule, the ionic charge is  If the interionic distance is  unit, then the dipole moment is

Q9

In which one of the following cases, breaking of covalent bond takes place?