Answer: 
Explanation:
Lattice energy : It is defined energy released when ions combine together in a gaseous phase to form a compound. it is energy possessed by the crystal lattice of a compound. Denoted by symbol
.
, energy is absorbed while forming of the lattice
, energy is release while forming of the lattice

One mole of sodium ion when combines with one mole chloride ion release 786 kJ of energy.
Answer is: 2,469 mL give to the child.
The mass m in kilograms (kg) is equal to the mass m in pounds (lb) times 0,45359237: m(child) = 72,6 · 0,045359237 = 32,93 kg.
m(Medrol) = 32,93 kg · 1,5 mg/kg.
m(Medrol) = 49,39 mg.
d(Medrol) = 20,0 mg/mL.
V(Medrol) = m(Medrol) ÷ d(Medrol).
V(Medrol) = 49,39 mg ÷ 20 mg/mL.
V(Medrol) = 2,469 mL.