Final answer:
CsBr, RbBr, and NaCl are arranged in increasing magnitude of lattice energy as CsBr < RbBr < NaCl, based on the size of the ions and the inverse proportionality of lattice energy to internuclear distance.
Step-by-step explanation:
The student's question relates to the concept of lattice energy in ionic compounds. Lattice energy is influenced by the charge on the ions and their sizes, as it is directly proportional to the product of the ionic charges and inversely proportional to the internuclear distance (the distance between the nuclei of the ions). To arrange CsBr, NaCl, and RbBr in increasing magnitude of lattice energy, we need to consider the charges and sizes of the ions.
Each compound contains ions with a charge of +1 and -1. Therefore, we will primarily look at the sizes of the ions to determine the lattice energy. As Cs+ is larger than Rb+, which in turn is larger than Na+, the lattice energy of CsBr will be the lowest, followed by RbBr, with NaCl having the highest lattice energy because smaller ions allow for a shorter internuclear distance, leading to a larger lattice energy.
Thus, the compounds arranged in order of increasing magnitude of lattice energy are: CsBr < RbBr < NaCl.