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This is one of our many quizzes on Serial dilutions. Click on this to access more such competitive quizzes on Physical Chemistry.

Serial dilutions Quiz 2

chemistry

 Aadra dilutes a stock solution in two-fold dilution, what is the composition of the solution formed:

 $Dilution\,factor=\dfrac{{{V}_{initial}}}{{{V}_{final}}}$

 The two-fold solution of dilution refers to the dilution in which the concentration of the solution is decreased by 2 times, i.e. the concentration of the new solution will be half the concentration of the first one. 

 In a serial dilution, the dilution factor:

   In serial dilution, the volume taken from each tube will be of the same volume.

 In each step, an equal quantity of the volume is taken and diluted. The volume taken for dilution will be the same for all the dilutions. Therefore, the dilution factor will remain constant.

 Adrika has a 50mL solution of KCl of 0.7M for her experiment, but she requires a solution of 0.35. What should be the volume of the new solution to have the required concentration?

 Use the equation, ${{M}_{1}}{{V}_{1}}={{M}_{2}}{{V}_{2}}$ for calculation.

 The equation used is: $ \\ {{M}_{1}}{{V}_{1}}={{M}_{2}}{{V}_{2}}\\ 0.7\times 50=0.3\times {{V}_{2}}\\ {{V}_{2}}=100mL$

  Ashish prepared a 2.5L stock solution of NaOH of 3.5M. What should be the amount of water added to obtain a solution of 2M?

  $ \\ {{M}_{1}}{{V}_{1}}={{M}_{2}}{{V}_{2}}$, M is molarity and V is volume of solution.

   The equation that should be used is $ \\ {{M}_{1}}{{V}_{1}}={{M}_{2}}{{V}_{2}}\\ 2.5\times 3.5=2\times {{V}_{2}}\\ {{V}_{2}}= \dfrac{ 2.5\times 3.5  }{2}\ \ =\ \  4.375 \\ $ The  final approx volume is $ 4.3 L$ and the initial volume is $2.5 L$. The difference between the final and initial volume of the solution gives the volume of water added. $ \\ {{V}_{water}}={{V}_{final}}-{{V}_{initial}}\\ {{V}_{water}}\ \ =\ \ 4.3 - 2.5 \ \ =\ \ 1.8 L$<br><br>

 Adwaith took 4 test tubes and he took 0.4ml from the stock solution and added it into tube 1 and added 0.6mL of water. He repeated the same twice. What will be the dilution factor after carrying out the whole dilution? $ \\ $ <img  src="https://cmds-vedantu.s3.ap-southeast-1.amazonaws.com/prod/question-sets/54d01aa1-a67f-4438-96dd-08381120d2704493448854736908397.png"/>

 Dilution factor is, $D.f=\dfrac{{{V}_{initial}}}{{{V}_{final}}}$

The dilution factor calculated as, $D.f=\dfrac{{{V}_{initial}}}{{{V}_{final}}}\\ $ Hence $ D.f=\dfrac{0.4}{4}=\dfrac{1}{10}\\ $ Four successive dilutions give, $\\ D.f=\dfrac{1}{10}\times \dfrac{1}{10}\times \dfrac{1}{10}\times \dfrac{1}{10}=\dfrac{1}{10000}$