Why is it okay to wash down the sides of the Erlenmeyer flask with DI water duri

Question

Why is it okay to wash down the sides of the Erlenmeyer flask with DI water during the titration, even though you are diluting the acid present? Calculate the following: a) How many moles of sodium hydroxide are present in 50.00 mL of 0.09899 M NaOH solution? b) A 25.00 mL sample of a hydrochloric acid solution of unknown concentration was titrated with 0.09899 M NaOH solution. Calculate the concentration of the acid if the initial burette reading is 2.14 mL and the burette reading when the endpoint was observed was 21.62 mL.

Explanation / Answer

1)

neutralization occurs only when

moles of acid = moles of base

the moles are constant, will not change as you add DI water, since it is only H2O

2)

V = 50 ml

V = 50/1000 = 0.05 V

M = 0.09899 M

then

mol = M*V = 0.09899 *0.05 = 0.0049495 mol of NaOH

2b)

V = 25 ml of HCl

M = 0.09899 M of NaOH

dV = Vf-Vi = 21.62 - 2.14 = 19.48 ml

v = 19.48/1000 = 0.01948

then

mol of acid = mol of base

[Acid] = mol of acid / V

mol of acid = mol of base = 0.0049495

[Acid] = mol of acid / V = 0.0049495 /(0.01948) = 0.2540

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

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