If 76 grams of nal are dissolved in enough water to make 225.0 ml of solution, what is the molarity of the solution? (2.25 mol/l)

2.25 M

Explanation:

Molarity of a substance , is the number of moles present in a liter of solution .

M = n / V

M = molarity  

V = volume of solution in liter ,

n = moles of solute ,

Moles is denoted by given mass divided by the molecular mass ,  

Hence ,  

n = w / m

n = moles ,  

w = given mass ,  

m = molecular mass .

From the question ,

w = given mass of Nal  = 76 g

and ,  

V =volume of solution =  225.0 mL

since ,

1 mL = 1 / 1000 L

V  = 225.0 / 1000 L = 0.225 L

Since ,  

we know ,

m = Molecular mass of NaI = 149.89 g / mol

using , the above formula to calculate the moles ,  

n = w / m = 76 g /  149.89 g/mol = 0.507 mol

now , calculating the molarity as ,

M = n / V = 0.507 mol  / 0.225 L = 2.25 M