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Starting with a 7. 0 x 10-5 M. Allura Red stock solution you will need to calculate the volumes required to prepare 10.00 mL solutions of 3.5 x 10-5 M, 2.8 x 10-5 M, 2.1 x 10-5 M, 1.4 x 10-5 M, and 3.5 x 10-6 M before coming to lab. What volume of the stock solution will be required to prepare 10.00 mL of a 2.1 x 10-5 M solution of Allura Red?

Answer :

Sebassandingo

Answer:

1) 5.0 mL, 4.0 mL, 3.0 mL and 2.0 mL respectively.

2) 3.0 mL

Explanation:

Hello there!

1) In this case, by considering that the equation we use for dilutions contain the initial and final concentrations and volumes:

[tex]C_1V_1=C_2V_2[/tex]

For the first four solutions, we compute the volume of the stock one (V1) as shown below:

[tex]V_1=\frac{C_2V_2}{C_1}[/tex]

Thus, we obtain:

[tex]V_1^1=\frac{3.5x10^{-5}M*10.00mL}{7.0x10^{-5}M} =5.0mL\\\\V_1^2=\frac{2.8x10^{-5}M*10.00mL}{7.0x10^{-5}M} =4.0mL\\\\V_1^3=\frac{2.1x10^{-5}M*10.00mL}{7.0x10^{-5}M} =3.0mL\\\\V_1^4=\frac{1.4x10^{-5}M*10.00mL}{7.0x10^{-5}M} =2.0mL[/tex]

2) In this case, for a final concentration of 2.1x10-5 M and a volume of 10.00 mL, the volume of the stock solution would be:

[tex]V_1=\frac{2.1x10^{-5}M*10.00mL}{7.0x10^{-5}M} =3.0mL[/tex]

Best regards!

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