B.P.S.C. TRE-3 July, 2024
Which of the following oxides is soluble in water?
aFeO
bZnO
cCaO✓ Correct
dMore than one of the above
eNone of the above
Explanation
Calcium oxide reacts with water to form calcium hydroxide [Ca(OH)₂]; hence it is treated as soluble in water, whereas FeO and ZnO are not soluble in water. CaO + H₂O → Ca(OH)₂ Therefore, the correct answer is option (c).
general-science