Final answer:
The compound that is insoluble in water at 25 degrees Celsius is B. Mg₃(PO₄)₂.
Step-by-step explanation:
The compound that is insoluble in water at 25 degrees Celsius is B. Mg₃(PO₄)₂.
Insoluble compounds are those that do not dissolve in water. In this case, magnesium phosphate, Mg₃(PO₄)₂, does not dissolve in water at this temperature.
Solubility is dependent on various factors such as temperature, pressure, and the nature of the compound.
While many inorganic compounds are soluble in water, there are exceptions, such as calcium carbonate (CaCO₃), which is insoluble.
It is important to study the solubility rules in chemistry to determine the solubility of different compounds.