Connecting lab to lecture #2 Part III: Follow-up questions should write Ka or so

Question

Connecting lab to lecture #2 Part III: Follow-up questions should write Ka or solution of odium nitrile, NaNO·has a pH of S7. showing . A 0.20 M solution of a. Write the chemical nitrile, ica, equutionshywing why this salt has the given pH (Mn, ~ on, how do you know which one?) anion and K·for the corresponding cory is formed, CH CIOOH. Kb chemical ted acid given the b. Calculate K. fr the 2 Ifome of the hydrogens bonded to the carbon atom in acetic acid is replaced by a ic acid a Draw the Lewis stracture for monochloroacetic acid. The pK, or morochlonwetic acid is 2.865 at 25"C Compare this pk. to that ofacetic acid and under the topic of strength of acids and molecular structure. c Estimate the pH of a 0.10 M monochloroacetic acid. What is the approximate percent of ionization for this acid? Connecting this lab to the lecture. Resuls must be reported to the coret number f 1) At 60 °C, K.-9.5x10, What is the pH of pure water at this temperature? Why can we say that significant figures. this water is neither acidic nor basic? 2) At 25 *C, the water in a natural pool of water in one of the western states was found to contain hydroxide ions at a concentration of 4.7x10-7g OH per liter a. Calculate the pH of this water b. State if it is acidic, basic, or neutral. 3) The first antiseptic to be used in surgical operating rooms was phenol, C,H,OH, a weak acid and a potent bactericide. A 0.550 M solution of phenol in water was found to have a pH of 5.07. a. Write the chemical equation for the equilibrium involving C H,OH in the solution. b. Write the equilibrium law corresponding to K,forcji0H

Explanation / Answer

2.

(a)

4.7 x 10-7 g OH- per liter

Mass of OH- = 4.7 x 10-7 g
Molar mass of OH- = 17 g/mol
So, moles of OH- = (4.7 x 10-7 g ) / (17 g/mol)
= 2.76 x 10-8 mol

Volume = 1 L

So, [OH- ] = (2.76 x 10-8 mol) / 1 L = 2.76 x 10-8 M

pOH = - log [OH- ]
= - log (2.76 x 10-8)
= 7.56

pH = 14 - pOH
= 14 - 7.56
= 6.44

(b)

pH = 7 (neutral)
pH > 7 (Basci)
pH < 7 (Acidic)

Since pH = 6. 44 < 7

So, it is acidic.

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

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