Question

Calculate the molarity of a solution made by adding 36.0 mL36.0 mL of concentrated hydrochloric acid ( 37.337.3 % by mass, density 1.19 g/mL1.19 g/mL ) to some water in a volumetric flask, then adding water to the mark to make exactly 2000 mL2000 mL of solution. (It is important to add concentrated acid or base to water, rather than the other way, to minimize splashing and maximize safety.)

Answer 1

Answer:

The molarity is 0.22 M.

Explanation:

The molarity of a solution can be calculated as follows:

$C = \frac{n}{V_{T}} = \frac{m}{M*V_{T}}$

Where:

n: is the number of moles

V(T): is the total volume = 2000 mL = 2 L  

M: is the molar mass = 36.46 g/mol      

m: is the mass

The mass of HCl can be found using the following equation:

$m = d*\% *V$      

Where:

d: is the density = 1.19 g/mL

V: is the volume = 36.0 mL  

% = 37.3 % by mass = 0.373    

$m = 1.19 g/mL*0.373*36.0 mL = 15.9 g$

Hence, the molarity is:

$C = \frac{m}{M*V_{T}} = \frac{15.9 g}{36.46 g/mol*2 L} = 0.22 mol/L$

Therefore, the molarity is 0.22 M.

I hope it helps you!