Solving questions. 2,3,4,5,6 Experiment #3 Determination of the pH value 1. Fill

Question

Solving questions. 2,3,4,5,6
Experiment #3 Determination of the pH value 1. Fill the below table: Substance pH value Condition (Acidic Cola Co ffee mil k S ooP or basic) Acid c Acid: natura baci acJ 2 3 2. How do you increase or decrease the pH of pure water? Determine which of the following is acid or base in terms of Bronsted-Lowry theory and why? A. Carbonic acid 3. B. Ammonium hydroxide 4. Which solution is more acidity with pH-1 or pH-5 in terms of Arrhenius theory? 5. Calculate the Molarity of Sulfuric acid if the pH-3? 6. Find the molality of hydrochloric acid with 500agi of solution and 20 g of solvent?

Explanation / Answer

2) To increase the pH of water you can add soap inside it since it is basic in nature. And to decrease the pH of water you can add Vinegar, coffee or cola which are acidic in nature.

3) The Bronsted-Lowry Theory of acids and bases-

An acid is a proton (hydrogen ion) donor.

A base is a proton (hydrogen ion) acceptor.

Carbonic Acid (H2CO3) - Bronsted Acid ( It can donate 2 H+ ions )

Ammonium Hydroxide (NH4OH) - Bronsted Base ( It can accept 1 H+ ion for 1 OH- ion )

4) The Arrhenius Theory of acids and bases -

Acids are substances which produce hydrogen ions in solution.

Bases are substances which produce hydroxide ions in solution.

More acidity means more power to produce H+ ions in solution.

pH = 1 ==> [H+] = 10-1 M

pH = 5 ==> [H+] = 10-5 M

So, pH=1 has more concentration of H+ ions which shows it has more acidity than pH=5.

5) pH = 3

[H+] = 10-pH = 10-3 M

Since sulfuric acid (H2SO4) is 2 molar with respect to H+,

[H2SO4] = (1/2) x 10-3

[H2SO4] = 5 x 10-4M

6) Molality = Moles of solute / Mass of solvent in kg

Mass of solvent = 20 g

Assuming the solvent is water,

Moles of solvent = 20 / 18 = 1.111

Moles of solute = 500 - 1.111 = 498.889

Mass of solvent in kg = 20/1000 = 0.02 kg

Molality = 498.889 / 0.02 = 24944.44 m

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

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