Question

the volume of water that must be added to a mixture of 250 ml of 0.6 M HCL and 750 ml of 0.2 M HCL to obtain 0.25 M solution of HCL

Answer 1

No. of moles of 0.6M HCl = 0.15

No. of moles of 0.2M HCl = 0.15

let V be the volume(in ml) of the 0.25M solution. No of moles present = 0.15+0.15 = 0.3



0.3*1000/v(ml) = 0.25 M

v = 1.2 lit.

Answer 2

Final answer: The volume of water to be added to obtain a $0.25$ $M$ final solution is $200$ $mL$.    

Given that: We are given a mixture of $250$ $mL$ of $0.6$ $M$ $HCl$ and $750$ $mL$ of $0.2$ $M$ $HCl$.

To find: We have to find the volume of water that must be added to a mixture of $250$ $mL$ of $0.6$ $M$ $HCl$ and $750$ $mL$ of $0.2$ $M$ $HCl$ to obtain $0.25$ $M$ solution of $HCl$.

Explanation:

• When two solutions of the same compound but they differ in molarity and volumes are added to obtain a new solution.

                     $M_{1}V_{1}+M_{2}V_{2}= M_{final}V_{final}$

• Let $M_{1}, M_{2}, V_{1}$ and $V_{2}$ are the molarity and volume of the solutions of same compound being mixed. And $M_{final}$ and $V_{final}$ are the molarity and volume of the final solution being formed.
• Here, two solutions of $HCl$ of different molarity and volume are mixed to form a new solution.

$M_{1}$ = $0.6$$M$

$M_{2}$ = $0.2$ $M$

$V_{1}$ = $250$ $mL$

$V_{2}$ = $750$ $mL$

$M_{final}$ = $0.25$ $M$

$V_{final}$ = ?

• Substitute these values in:

                      $M_{1}V_{1}+M_{2}V_{2}= M_{final}V_{final}$

                 $(0.6\times250)+(0.2\times750)=0.25\times V_{final}$

                               $150+150=0.25\times V_{final}\\\\300=0.25\times V_{final}$

                               $V_{final}=\frac{300}{0.25}$

                               $V_{final}=1200$ $mL$

• Total volume of the final solution $V_{final}$ = $1200$ $mL$

• The volume of the solution initially mixed, $V_{initial}=V_{1}+V_{2}$

                                                                  $= 250+750=1000$ $mL$

• The volume of water we need to add to the initial solution to make the final solution = $V_{final}-V_{initial}$

                                                 = $1200-1000$

                                                 = $200$ $mL$

• Hence, the volume of water to be added to obtain a $0.25$ $M$ final solution is $200$ $mL$.

To know more about the concept please go through the links

https://brainly.in/question/3206766

https://brainly.in/question/19654715

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