Question

4. Chemical formula, mg (Cl0₃)2
a) calculate the number of moles for 3.24g, Mg (Cl03)2
b) calculate the molarity of mg (Cl03)2 if all of it were dissolved in
5.08 L distilled water.​

Answer 1

Answer:

0.017mole

0.0033M

Explanation:

Given parameters:

Formula of the compound:

           Mg(ClO₃)₂

Mass of the sample  = 3.24g

Unknown:

Number of moles of the sample = ?

Molarity  = ?

Solution:

The number of moles of any substance is given as:

   Number of moles  = $\frac{mass}{volume}$  

 Molar mass of Mg(ClO₃)₂  = 24 + 2[35.5 + 3(16)]  = 191g/mol

    Number of moles  = $\frac{3.24}{191}$   = 0.017mole

Molarity is the number of moles of a solute in a solution:

    Molarity  = $\frac{number of moles }{volume}$  

 Volume given  = 5.08L

  Molarity  = $\frac{0.017}{5.08}$  = 0.0033M