Chapter 17, Problem 66A

Interpretation Introduction

Interpretation:

The reason for barium sulfate to be better than barium chloride for adding definition to x rays needs to be explained.

Concept introduction:

Higher the solubility of a contrasting agent in a solvent, the less safer it becomes for x ray contrasting.

Answer to Problem 66A

Barium sulfate is better choice than barium chloride for adding definition to x rays because it is less soluble in water than barium chloride in water and hence is safer to use.

Explanation of Solution

Equation for barium sulphate in water:

$BaS{O}_4\to B{a}^{2+}+S{O}_4{}^{2-}$

Solubility product for barium sulphate:

$\begin{array}{l}{K}_{sp}=[B{a}^{2+}][S{O}_4{}^{2-}]\\ K_{sp}=S^2\\ S=\sqrt{K_{sp}}\\ S=\sqrt{1.1\times {10}^{-10}}\\ S=1.05\times {10}^{-5}\end{array}$

From above solubility, we found that barium sulphate is less soluble than barium chloride and is much safer to use.

Conclusion

The preference of barium sulfate over barium chloride is due to its less solubility.