In order to create a new solution of sodium hydroxide, a 6.00 M solution was use

Question

In order to create a new solution of sodium hydroxide, a 6.00 M solution was used as the stock solution. If a total of 2.00 L of ~0.2 M NaOH is necessary, how many mL of the stock sodium hydroxide should be used to create this solution? Using the volume from the above question, calculate the real molarity of the NaOH that would be created using a 6.00 M solution and diluting it to 2.00 L. Assume we only have pipets for whole numbers capable of transferring whole number mL. (Remember: volumetric pipets have significant figures to the hundredths place.) Why can't the solution made in Part B be tested to find the concentration experimentally by titration with NaOH? 25.00 ml, of a solution that contains an unknown amount of acetic acid is tested via titration with sodium hydroxide. Write the balanced chemical equation for this reaction. The sodium hydroxide bad previously been standardized to lie 0.1588 M and the titration required 22.54 mL. What is the mass of acetic acid present in the unknown?

Explanation / Answer

1)

M = 6 Stock solution

We need V = 2 L of 0.2 M of NaOH

Apply dilution law

M1*V1 = M2*V2

6M*V1 = 0.2M*2L

V1 = 0.06667 L or 66.67 ml

2)

Calculate molarity

M1*V1 = M2*V2

M2 = V1/V2*M1 = (0.06667)/2 * 6 = 0.20 +/- 0.01

M2 = 0.2 +/- 0.01

3)

It can't be used since it is not precise, or not exact. We are going to interact with volumes of "ml" and moles in "millimol" which are pretty small. Pipets can't measure those quantities

4)

V = 25 ml

a) reaction

CH3COOH(aq) + NaOH(aq) <-> H2O(l) + NaCH3COO(aq)

b)

M = 0.1577 M of NaOH

V = 22.54 ml of base

find the mass of acetic acid

this is given in the equivalence point

Moles of Acid = Moles of Base

Moles of Base = M*V = 0.1588M*22.54ml = 3.5794 mmol of base

therefore we have 3.5794 mmol of acid

MW of Acetic Acidd = 60.1 g/mol

mass = mol*MW = (3.5794*10^-3 mol)*60.1 g/mol = 0.2151 grams of Acetic acid

mass of acetic acid = 0.2151 g

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.