Question

How many grams of Sodium hydroxide are present in 750.0 mL of 2.5 M sodium hydroxide solution?

Answer 1

75 g of sodium hydroxide is present in the solution.

Explanation :

Given :

Molarity  of sodium hydroxide solution= 2.5 M

Litres of Solution = 750 mL

Molar mass of NaOH = 40 g/mol

To Find:

Grams of Sodium Hydroxide =?

Solution :

Molarity of the solution is expressed in Litres, So Converting 750.0 mL to Litres we have

750.0mL=0.750 Litres

Grams of Solution ,  moles= $M\times L$

Where  

M = Molarity  

L = litres of solution

mol= moles of solute

$mol= 2.5 \times \frac{750}{1000}$

Mol = 1.875  

Also the molecular weight of NaOH is  40.00 g/mol

Grams of sodium hydroxide = 1.875 mol * 40.00 g/mol = 75 g