Question

Calculate the molarity of a solution prepared by dissolving 11.5 g naoh in enough water to make 1.5 l of solution. 1. 7.6 m 2. 2.3 m 3. 0.19 m 4. 0.43 m

Answer 1

Molarity of a solution = (number mol of solute)/ (volume of the solution)

1) Molar mass NaOH= M(Na)+M(O)+M(h)= 23.0+16.0+1.0=40.0 g/mol
2) 11.5 g NaOH *(1mol Naoh/40.0 g NaOH)=0.288 mol NaOH
3)Molarity (NaOH solution) =(0.288 mol)/(1.5 L)=0.192 M≈0.19 M

Answer 2

Answer: The molarity of the solution is 0.19 M

Explanation:

To calculate the molarity of the solution, we use the equation given as:

$\text{Molarity}=\frac{\text{Mass of solute(in grams)}}{\text{Molar mass of solute(in g/mol)}\times \text{Volume of solution (in L)}}$

We are given:

Mass of NaOH = 11.5 g

Molar mass of NaOH = $[23+16+1]g/mol=40g/mol$

Volume of the solution = 1.5 Liters

Putting values in above equation, we get:

$\text{Molarity of solution}=\frac{11.5g}{40g/mol\times 1.5L}=0.19mol/L=0.19M$

Hence, the molarity of the solution is 0.19 M