Please answer and show work! Thank you You are instructed to create 170 mL of a

Question

Please answer and show work! Thank you

You are instructed to create 170 mL of a 0.06 M Acetate buffer with a pH of 4.1. You have Acetic acid and the sodium salt NaC_2H_3O_2, available. (Enter all numerical answers to three significant figures.) Write the results of your calculations in your lab notebook for use during lab. HC_P2H_2O_2(s) + H_2O(l) H_2O^+(aq) + C_2H_3O^-_2(aq) K_ = 1.7 times 10^-5 What at the molarity needed for the acid component of the buffer? What is the molarity needed for the base component of the buffer? How many moles of acid are needed for the buffer? How many moles of base ere needed for buffer? How many grams or acid are needed for the buffer? How many grams of base are needed for the buffer?

Explanation / Answer

Using Hendersen Hasselbalck equation,

pH = pKa + log(base/acid)

with,

pH = 4.1 ; pKa = 4.75

[acid] = HC2H3O2 ; [base] = NaC2H3O2

we get,

4.1 = 4.75 + log(NaC2H3O2/HC2H3O2)

NaC2H3O2 = 0.224(HC2H3O2)

and,

(HC2H3O2) + (NaC2H3O2) = 0.06 M x 170 ml = 10.2 mmol

so,

(HC2H3O2) + 0.224(HC2H3O2) = 10.2 mmol

moles of acid component needed for the buffer (HC2H3O2) = 10.2 mmol/1.224 x 1000 = 0.0083 mol

moles of base component needed for the buffer (NaC2H3O2) = (10.2 mmol - 0.0083)/1000 = 0.0019 mol

molarity of acid component needed for the buffer (HC2H3O2) = 0.0083 mol/0.170 L = 0.0488 M

moles of base component needed for the buffer (NaC2H3O2) = 0.0019 mol/0.170 L = 0.0112 M

Grams of acid component needed for the buffer (HC2H3O2) = 0.0083 mol x 60.05 g/mol = 0.498 g

Grams of base component needed for the buffer (NaC2H3O2) = 0.0019 mol x 82.03 g/mol = 0.156 g

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---