Question

Ba, Ca, Sr form halide hydrates. Their formulae are \( BaCl_2 \cdot xH_2O \), \( CaCl_2 \cdot yH_2O \), \( SrCl_2 \cdot zH_2O \). The values of \( x, y, z \) respectively are:

• A. \( 2, 6, 6 \)
• B. \( 8, 6, 4 \)
• C. \( 8, 6, 6 \)
• D. \( 6, 4, 2 \)

Hint:

Hydration numbers of alkaline earth metal chlorides depend on their size and charge density. BaCl\(_2\) forms a dihydrate, whereas CaCl\(_2\) and SrCl\(_2\) form hexahydrates.

Answer 1

The Correct Option is A

The problem involves halide hydrates of barium, calcium, and strontium. We need to determine the hydration numbers \( x, y, z \) for the compounds \( BaCl_2 \cdot xH_2O \), \( CaCl_2 \cdot yH_2O \), and \( SrCl_2 \cdot zH_2O \) respectively.

Let's evaluate the options provided:

• Option 1: \( x=2, y=6, z=6 \) 
• Option 2: \( x=8, y=6, z=4 \)
• Option 3: \( x=8, y=6, z=6 \)
• Option 4: \( x=6, y=4, z=2 \)

From chemical literature, we know:

• Barium chloride dihydrate is \( BaCl_2 \cdot 2H_2O \), hence \( x=2 \).
• Calcium chloride commonly forms a hexahydrate, which is \( CaCl_2 \cdot 6H_2O \), hence \( y=6 \).
• Strontium chloride forms a hexahydrate \( SrCl_2 \cdot 6H_2O \), hence \( z=6 \).

Given this information, the only correct option is:

x	y	z
2	6	6

The values are indeed \( x=2, y=6, z=6 \), which matches Option 1.

Answer 2

The question states that Barium (Ba), Calcium (Ca), and Strontium (Sr) form halide hydrates with the formulas \(BaCl_2 \cdot xH_2O\), \(CaCl_2 \cdot yH_2O\), and \(SrCl_2 \cdot zH_2O\). It asks for the values of x, y, and z.

The common halide hydrates formed by these alkaline earth metals are:

• \(BaCl_2 \cdot 2H_2O\) (Barium chloride dihydrate)
• \(CaCl_2 \cdot 6H_2O\) (Calcium chloride hexahydrate)
• \(SrCl_2 \cdot 6H_2O\) (Strontium chloride hexahydrate)

Therefore, x = 2, y = 6, and z = 6.