Moderate

Magnesium oxide is used in the making of the lining of the blast furnace.It is extracted from seawater as follows. Aqueous seawater is added to seawater. Ca(OH)2(aq)+MgCl2 (aq)-------->Mg (OH)2(s) + CaCl2 (aq). The magnesium hydroxide is then filtered off and roasted. Which of the following comparisons between calcium and magnesium explains why magnesium hydroxide forms?

Correct answer: A. The solubility product for Mg(OH)2 is lower than that for Ca(OH)2

  • A. The solubility product for Mg(OH)2 is lower than that for Ca(OH)2
  • B. The atomic radius of Mg is smaller than that of Ca.
  • C. Magnesium is more reactive than calcium.
  • D. Calcium has a higher ionization energy than magnesium.

Explanation

This is the correct answer. As discussed previously, solubility product (Ksp) plays a crucial role in determining the extent to which an ionic compound dissolves in water. A lower Ksp signifies lower solubility. In this case, Mg(OH)2 has a lower Ksp compared to Ca(OH)2. This means Mg(OH)2 precipitates more readily from the solution when Ca(OH)2 is added, even though both Ca and Mg compete with the hydroxide ions.

Last updated

About s-Block and p-Block Elements

The s and p blocks are studied through their valence-shell configurations, periodic trends and characteristic chemical properties. Work covers the reactions of Group I and Group II elements, the behaviour of Group IV elements, and how atomic size, ionization energy, electronegativity and metallic character change across periods and down groups.

Practise s-Block and p-Block Elements

1,359 free s-Block and p-Block Elements MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Exams that ask Chemistry questions like this

Chemistry is on 12 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

Related questions