Answer to Question #118857 in General Chemistry for queen

Question

You must prepare a 100mL solution of hydrochloric acid with a concentration of 0.500mol/L. Your are given the appropriate glassware and a bottle of 0.250 mol/L stock hydrochloric acid. What must you use to prepare the solution

Answer 1

Solution.

$V_1=100mL=0.1L;$

$c_1=0.500mol/L;$

$c_2=0.250mol/L;$

$V_2-?;$

$c_1V_1=c_2V_2,$

$c_1,V_1$  - the molarity and volume of the concentrated solution;

$c_2,V_2$ - the molarity and volume of the diluted solution;

$V_2=\dfrac{c_1V_1}{c_2};$

$V_2=\dfrac{0.500mol/L\sdot0.1L}{0.250mol/L}=0.2L;$

It is impossible to prepare such a solution, because it is necessary to take twice as much acid as the volume of the whole solution should be, because pure acid has twice less concentration than dilute.

Answer: It is not possible to prepare the solution.