All of them are soluble salt.
First one dissociates into two ions.
The second one dissociates into 3 ions.
The third dissociate into 4 ions. therefore, Al(NO3)3
When the block of iron is placed in water the volume of water that is displaced is 27.0 cm³
<u><em> calculation</em></u>
The volume water that is displaced is equal to volume of block of the iron
volume of block of iron = length x width x height
length= 3 cm
width = 3 cm
height = 3 cm
volume is therefore = 3 cm x 3 cm x 3 cm = 27 cm³ therefore the volume displaced = 27 cm³ since the volume of water displaced is equal to volume of block.
