I am sorry bro I don't know
Well since i need points I am going to say read the text
Calcium Hydroxide (Ca(OH)2) reacts with the Carbon Dioxide (CO2) present in the Air to form Calcium Carbonate (CaCO3) and Water (H2O).
The equation looks something like this -->
Ca(OH)2 + CO2 = CaCO3 + H2O
Answer: Magnet
Explanation:Using a magnet is the best separating technique to be deployed in this case. The nails are easily picked out by just holding a magnet over the sandbox.
Ni(OH)2+H2SO4=NiSO4+2H2O
Double Replacement Reaction