Answered

PLEASE ANSWER I AM BEGGING

How many milliliters of a stock solution of 7.00 M HNO3 would you have to use to prepare 0.120 L of 0.480 M HNO3 ? If you dilute 20.0 mL of the stock solution to a final volume of 0.270 L , what will be the concentration of the diluted solution?



Answer :

CintiaSalazar

Taking into account the definition of dilution:

  • you have to use 8.23 mL of a stock solution of 7.00 M HNO₃ to prepare 0.120 L of 0.480 M HNO₃.
  • If you dilute 20.0 mL of the stock solution to a final volume of 0.270 L , the concentration of the diluted solution is 0.518 M.

Dilution

Dilution is the process of reducing the concentration of solute in solution, which is accomplished by simply adding more solvent to the solution at the same amount of solute.

In a dilution the amount of solute does not change, but as more solvent is added, the concentration of the solute decreases, as the volume (and weight) of the solution increases.

A dilution is mathematically expressed as:

Ci×Vi = Cf×Vf

where

  • Ci: initial concentration
  • Vi: initial volume
  • Cf: final concentration
  • Vf: final volume

Volume of stock solution

In this case, you know:

  • Ci= 7 M
  • Vi= ?
  • Cf= 0.480 M
  • Vf= 0.120 L

Replacing in the definition of dilution:

7 M× Vi= 0.480 M× 0.120 L

Solving:

Vi= (0.480 M× 0.120 L)÷ 7 M

Vi= 0.00823 L= 8.23 mL (being 1 L= 1000 mL)

Finally, you will need 8.23 mL of the stock solution.

Concentration of the diluted solution

In this case, you know:

  • Ci= 7 M assuming the stock solution is 7.00 M HNO₃
  • Vi= 20 mL= 0.02 L
  • Cf= ?
  • Vf= 0.270 L

Replacing in the definition of dilution:

7 M× 0.02 L= Cf× 0.270 L

Solving:

(7 M× 0.02 L)÷ 0.270 L= Cf

0.518 M= Cf

Finally, the concentration is 0.518 M.

Learn more about dilution:

brainly.com/question/13505906

brainly.com/question/6692004

brainly.com/question/11931563

brainly.com/question/16343005

brainly.com/question/24709069

#SPJ1

Other Questions