Rank the following compounds in order of increasing solubility in water. Items (4 items) (Drag and drop into the appropriate area) No more items Items in order most soluble CaO BaO KCI KI I have tried CaO> BaO > KCl > KI, this is incorrect.

CaO < BaO < KCl <KI

Explanation:

Let us remember that the solubility of an ionic substance in water depends on the magnitude of the lattice energy and the hydration energy.  If the hydration energy is equal to or is greater than the lattice energy, the substance dissolves in water.

However, the lattice energy depends on the size of the ions. The smaller the ions in the ionic compound, the higher the lattice energy and the lesser the solubility of the ionic compound.

KI has the least lattice energy and the highest solubility in water while CaO has the highest lattice energy and the least solubility in water.

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o