Explain how to write the chemical formula for sodium (Na +) and the polyatomic ion carbonate (Co2).

Explanation:

sodium (Na +)

Carbonate ion (CO₃²⁻)

Ionic compounds are formed between ions (Anions and Cations).

For a neutral compound to be formed, the charges of the ions must cancel each other out.

Sodium ion has a charge of +1

Carbonate ion has  a charge of -2

The only way to make sure both ions have similar charges is to multiply each ion by the coefficient of the other.

Thus we have;

Sodium ion = +1 * 2 = +2

Carbonate ion = -2 * 1 = -2

From this, the chemical formular of the product formed between both ions must contain 2 sodium ions and one carbonate ion.

This is given by;

Na₂CO3

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"