MCAT General Chemistry Question 228: Answer and Explanation
Home > MCAT Test > MCAT general chemistry practice tests
Test Information
- Use your browser's back button to return to your test results.
- Do more MCAT general chemistry practice tests.
Question: 228
6. Which of the following salts is least soluble in water?
- A. PbI2 (Ksp = 7.9 × 10-9)
- B. Mg(OH)2 (Ksp = 6.3 × 10-10)
- C. Zn(IO3)2 (Ksp = 3.9 × 10-6)
- D. SrF2 (Ksp = 2.6 × 10-9)
Correct Answer: B
Explanation:
B All of the compounds are composed of one cation and two anions, so comparing Ksp values will give relative solubility. Since the question asks for an extreme, the middle values of the variable cannot be correct, eliminating choices A and D. The compound with the lowest Ksp value will have the lowest solubility because for all the compounds, Ksp = [cation][anion]2. Therefore, choice B is correct.