which compound has the highest melting point?\no al₂(co₃)₃\no c₁₂h₂₂o₁₁\no c₈h₁₈\no h₂o

Answer

Brief Explanations:

Aluminum carbonate ($Al_2(CO_3)3$) is an ionic compound. Ionic compounds generally have high melting - points due to strong electrostatic forces between ions. Sucrose ($C{12}H_{22}O_{11}$) and octane ($C_8H_{18}$) are covalent compounds with weaker intermolecular forces. Water ($H_2O$) also has relatively weak intermolecular hydrogen - bonding forces compared to the ionic bonds in $Al_2(CO_3)_3$.

Answer:

A. $Al_2(CO_3)_3$