Chemistry, 28.07.2021 03:00, nauticatyson9

An analytical chemist is titrating of a solution of benzoic acid with a solution of . The of benzoic acid is . Calculate the pH of the acid solution after the chemist has added of the solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of solution added.

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answered: connersitte1221l

The question is incomplete. The complete question is :

An analytical chemist is titrating 148.9 mL of a 1.100 M solution of benzoic acid $HC_6H_5CO_2$ with a 0.3600 M solution of KOH. The pK_a of benzoic acid is 4.20. Calculate the pH of the acid solution after the chemist has added 232.0 mL of the KOH solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of KOH solution added.

Solution :

Number of moles of $C_6H_5OCOOH$ $=148.9 \ mL \times \frac{L}{1000\ mL} \times \frac{1.100 \ mol}{L}$

= 0.16379 mol

Number of moles of NaOH added $=232.0 \ mL \times \frac{L}{1000\ mL} \times \frac{0.3600 \ mol}{L}$

= 0.08352 mol

ICE table :

$C_6H_5OCOOH \ \ \ + \ \ \ OH^- \ \ \ \rightarrow \ \ C_6H_5OCOO^- \ \ \ \ + \ \ H_2O$

I (mol) 0.16379 0.08352 0

C (mol) -0.08352 -0.08352 +0.08352

E (mol) 0.08027 0 0.08352

Total volume = (148.9 + 232) mL

= 380.9 mL

= 0.3809 L

Concentration of $C_6H_5OCOOH, [C_6H_5OCOOH]$ $=\frac{0.08027 \ mol}{0.3809 \ L}$

= 0.211 M

Concentration of $$C_6H_5OCOO^- , [C_6H_5OCOO^-] =\frac{0.08352 \ mol}{0.3809 \ L}$

= 0.219 M

pK_a of C_6H_5OCOOH = 4.20

According to Henderson equation,

$$pH = pK_a + \log \frac{[C_6H_5OCOO^-]}{[C_6H_5OCOOH]}$

$=4.20 + \log \frac{0.219}{0.211}$

= 4.22

Therefore, the pH of the acid solution is 4.22

answered: Guest

58750.08068 is the answer i think

answered: Guest

Mass is the amount of matter in an object. weight is the measurement of the pull of gravity on an object. say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165) now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon. however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant. in conclusion it is possible for your weight to change as your mass remains constant.