Question

use the cross over method to find the chemical formula of sodium chloride and magnesium chloride

Answer 1

 Cross over method---->

a) NaCl

b) MgCl2

a) Valency of Na is 1 and valency of Cl is also 1.

So, the formula is NaCl

b) Valency of Mg is 2 and valency of Cl is 1.

So, the formula is MgCl

Explanation

If you mix two compounds to form something new, then the new compound has a different chemical composition than the two original compounds. People can use the cross over method to determine formulas for ionic compounds. You need to use a valency table to tell you how many ions an element has and the positive or negative charge on the ions. Once you find the new compound's formula, you can determine what you've created. For example, when you combine sodium (Na) and chloride (Cl), you get NaCl, which is salt.

Look up the chemical symbol of the compounds you are using. You can use a periodic table, located in the references, to tell you the chemical symbol. For example, if you have sodium and oxygen, their chemical symbols are Na and O respectively.

Write out the chemical symbol for each compound being mixed. Use the valency table, located in the references, to find and write the valency of the compound next to its chemical symbol. A valency table lists compounds by there names or symbols. The valence tells you how many free ions the compound has. For example, if you are mixing sodium and oxygen, you would write Na +1, O -2. This means sodium has a valence of +1 and oxygen has a valence of -2.

Answer 2

Explanation:

Hope it helped.........