What happens when equal volumes of 0.2M Na2SO3 and 0.2M CaSO3 are mixed?
A. Only Na2S precipitates.
B. Only CaSO3 precipitates.
C. Both CaSO3 and Na2S precipitate.
D. No precipitate forms.
I wonder if you have typed the question incorrectly because the question has Na2SO3 and CaSO3 in it but the answers allude to Na2S and CaSO3.
To determine what happens when equal volumes of 0.2M Na2SO3 and 0.2M CaSO3 are mixed, we need to consider the solubility of the compounds involved.
Na2SO3 (sodium sulfite) and CaSO3 (calcium sulfite) are both salts that can potentially form precipitates if they are not highly soluble in water.
To determine if a precipitate will form, we need to compare the solubility product constants (Ksp) of the compounds.
The solubility product constant is an equilibrium constant that describes the extent to which a sparingly soluble compound dissolves in water. If the concentration of the dissolved ions exceeds the solubility product constant, a precipitate will form.
Let's look up the solubility product constants for Na2SO3 and CaSO3:
- The solubility product constant for Na2SO3 is not readily available. However, based on general knowledge, Na2SO3 is known to be highly soluble in water. Therefore, we can assume that it will stay in solution and not form a precipitate.
- The solubility product constant for CaSO3 is also not readily available and can vary depending on temperature. However, based on general knowledge, CaSO3 is considered to be sparingly soluble in water. Therefore, there is a higher possibility that CaSO3 will form a precipitate when the concentration of dissolved ions exceeds its solubility product constant.
Thus, we can conclude that when equal volumes of 0.2M Na2SO3 and 0.2M CaSO3 are mixed, there is a higher chance for CaSO3 to precipitate, and Na2SO3 will remain in solution.
Therefore, the correct answer is B. Only CaSO3 precipitates.