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2 years ago

Calculate the ratio of ch3nh2 to ch3nh3cl required to create a buffer with ph = 10.12.

1 answer:

8 0

Hello!

From tables, we know that the pKa for Methylamine CH₃NH₂ is 10,61. Now, we can apply the Henderson-Hasselbach's equation and clear for the ratio of CH₃NH₂ to CH₃NH₃Cl

$pH=pKa + log( \frac{[CH_3NH_2]}{CH_3NH_3Cl} ) \\ \\ \frac{[CH_3NH_2]}{CH_3NH_3Cl}= 10^{pH-pKa}= 10^{10,12-10,61}=0,32$

So, the ratio of CH₃NH₂ to CH₃NH₃Cl should be 0,32

Have a nice day!

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Answer: The weight/weight % or percent by mass of the solute is 5.41 %.

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