Question

Consider these compounds: A. Fe2S3 B. Zn3(PO4)2 C. CrPO4 D. CaCO3 Complete the following statements by entering the letter corresponding to the correct compound. Without doing any calculations it is possible to determine that cobalt(II) carbonate is more soluble than , and cobalt(II) carbonate is less soluble than . It is not possible to determine whether cobalt(II) carbonate is more or less soluble than by simply comparing Ksp values.

Answer 1

Answer:

Filling in the blank:

Without doing any calculations (using tables) it is possible to determine that cobalt(II) carbonate (CoCO3) is more soluble than A, B, C, and cobalt(II) carbonate is less soluble than D. It is not possible to determine whether cobalt(II) carbonate is more or less soluble than by simply comparing Ksp values.

Explanation:

Ksp (Solubility product constant) is a constant indicating the equilibrium between a solid and its respective ions in a solution. The higher the Ksp the more soluble or dissociation the compound is in water.

Using ksp table (at 25°C)

$Fe_{2} S_{3} =$ 1.4 × $10^{-88}$

Zn3(PO4)2 = 9.1 ×$10^{-33}$

CrPO4 = 2.4 × $10^{-23}$

CaCO3 = 3.36 ×$10^{-9}$

CoCO3 = 1.0 × $10^{-10}$

Answer 2

Answer:

See explanation

Explanation:

Cobalt II carbonate is more soluble than iron III sulphide, Zn3(PO4)2 and CrPO4

Cobalt II carbonate is less soluble than calcium carbonate.

The ksp of the compounds were compared and this is the order of solubility as shown above.

Ksp shows the degree of solubility of an ionic compound. The lower the ksp, the lesser the solubility of the compound. Compounds with very low ksp are normally termed 'insoluble' in water.