Question

Salt ($\text{X}$) is soluble in water. Salt ($\text{Y}$) is sparingly soluble in water. Salt ($\text{Z}$) is soluble only in hot water. $\text{X}, \text{Y}, \text{Z}$ respectively are.

• A. $\text{AgCl}, \text{Hg}_2\text{Cl}_2, \text{PbCl}_2$
• B. $\text{AlCl}_3, \text{AgCl}, \text{PbCl}_2$
• C. $\text{BaCl}_2, \text{PbCl}_2, \text{Hg}_2\text{Cl}_2$
• D. $\text{MgCl}_2, \text{Hg}_2\text{Cl}_2, \text{CaCl}_2$

Hint:

Solubility rules for Group 1 metal ions ($\text{Ag}^+, \text{Pb}^{2+}, \text{Hg}_2^{2+}$) are essential. $\text{PbCl}_2$ is uniquely distinguished by its significant solubility increase upon heating.

Answer 1

The Correct Option is B

To determine which of the given salts corresponds to $\text{X}$ (soluble in water), $\text{Y}$ (sparingly soluble in water), and $\text{Z}$ (soluble only in hot water), let's analyze the solubility properties of each compound listed in the options.

1. Solubility in Water:
   • $\text{X}$: Salt that is soluble in water. In the list of options, \(\text{AlCl}_3\) (aluminum chloride) is known to be highly soluble in water.
   • $\text{Y}$: Salt that is sparingly soluble in water. Among the listed compounds, \(\text{AgCl}\) (silver chloride) is well-known for being sparingly soluble in water.
   • $\text{Z}$: Salt that is soluble only in hot water. Lead chloride, \(\text{PbCl}_2\), is known for its unique solubility property; it is sparingly soluble in cold water but becomes more soluble in hot water.
2. Analyzing the Options:
   • Option 1: $\text{AgCl}$, $\text{Hg}_2\text{Cl}_2$, $\text{PbCl}_2$. - $\text{AgCl}$ is indeed sparingly soluble, but $\text{Hg}_2\text{Cl}_2$ is neither highly soluble in water nor only soluble in hot water.
   • Option 2: $\text{AlCl}_3$, $\text{AgCl}$, $\text{PbCl}_2$. - Matches perfectly with the properties discussed: $\text{AlCl}_3$ is soluble in water, $\text{AgCl}$ is sparingly soluble, and $\text{PbCl}_2$ is soluble in hot water.
   • Option 3: $\text{BaCl}_2$, $\text{PbCl}_2$, $\text{Hg}_2\text{Cl}_2$. - $\text{BaCl}_2$ is soluble, but $\text{Hg}_2\text{Cl}_2$ does not fit the hot water solubility requirement.
   • Option 4: $\text{MgCl}_2$, $\text{Hg}_2\text{Cl}_2$, $\text{CaCl}_2$. - $\text{MgCl}_2$ is soluble in water, but again, $\text{Hg}_2\text{Cl}_2$ and $\text{CaCl}_2$ don't match the required descriptions.
3. Conclusion: Based on the reasoning above, Option 2 is the correct choice, where $\text{AlCl}_3$ is soluble in water, $\text{AgCl}$ is sparingly soluble, and $\text{PbCl}_2$ is soluble only in hot water.