Question

Write down the formulae of

(iv) Magnesium hydroxide

Answer 1

Chemical formula:

• The chemical formula of ionic compounds is generally written by using the Criss-cross method.
• In Criss-cross method, the ionic charge on ions of two atoms are crisscrossed so that they become the subscripts of the other ions.

Steps involved:

Step 1: Write down the ions with their ionic charges

Step 2: Apply the criss cross method

Step 3:The cation (positive) charge becomes the anion subscript (negative charge)

Step 4:The anion charge becomes the cation's subscript

Step 5: Write the chemical formula formed by the criss-cross method

(iv) Magnesium hydroxide

Step 1: The ionic charge of the Magnesium ion is $2+$ and the hydroxide ion has a charge of $1-$

Step2: By Using the criss-cross method

Step 3: The formula of Sodium oxide will be $\mathbf{Mg}{\left(\mathrm{OH}\right)}_{\mathbf{2}}$.