Answer:
Neutral
Step-by-step explanation:
We can consider this salt as a neutral one. It can be prepared by a neutralization reaction between the base and the acid.
CsOH + HBr → H₂O + CsBr
As the two reactants are strong, the HBr as a strong acid, and the CsOH as a strong base, the ions are considered as: the weak conjugate acid and the weak conjugate base.
Br⁻ + H₂O ← HBr + OH⁻
Cs⁺ + H₂O ← CsOH + H⁺
They can not react to water, that's why the salt is neutral (similar as the NaCl)
pH = 7