Question

question 17 of 20 :
select the best answer for the question.

1. which of the following notations is the appropriate and final way to display the formula for magnesium chloride?

a. mgcl₂
b. mgcl₂
c. mgcl
d. mg⁺²cl⁻¹
mark for review (will be highlighted on the review page)
<< previous question
next question >>

Explanation:

To determine the correct formula for magnesium chloride, we analyze the charges of the ions. Magnesium (\(Mg\)) has a +2 charge (\(Mg^{2+}\)) and chloride (\(Cl\)) has a -1 charge (\(Cl^-\)). To balance the charges, we need 2 chloride ions for each magnesium ion.

• Option A: \(MgCl_2\) has 1 \(Mg^{2+}\) and 2 \(Cl^-\), which balances the charges (2+ + 2×(-1) = 0).
• Option B: Chemical symbols are case - sensitive. Magnesium is \(Mg\), not \(MG\), so this is incorrect.
• Option C: \(MgCl\) would have a charge of 2+ + (-1)= +1, which is unbalanced, so this is wrong.
• Option D: The final formula for an ionic compound is written with the cation first and the anion second, using subscripts to show the ratio of ions, not showing the charges in the final formula. So this is incorrect.

Answer:

A. \(MgCl_2\)