Proton Transfer Reactions (HL IB Chemistry)

The aromatic compound phenol, C₆H₅OH, behaves as a weak acid, due the presence of a hydroxyl group on the benzene ring. What is the correct formula of the conjugate base formed when phenol dissociates?

What is the sum of the coefficients when the following acid-base equation is balanced?

_Al₂(CO₃)₃ (s) + _HNO₃ (aq)  ⇌ _Al(NO₃)₃ (aq) + _H₂O (l) +  _CO₂ (g)

Which of the following substances can be used to prepare magnesium sulfate by a neutralization reaction with dilute sulfuric acid?

1. Mg
2. MgO
3. MgCO₃

Phosphoric acid is a polyprotic acid and can produce amphiprotic species when it dissociates. Which of the following species is amphiprotic?

1. HPO₄²⁻
2. H₂PO₄⁻
3. PO₄³⁻

Use the following reactions to answer the question below:

H₂O (l) + F^- (aq) ⇌ HF (aq) + OH^- (aq)

H₂O (l) + HNO₃ (aq) → H₃O⁺ (aq) + NO₃^- (aq)

H₂O (l) + CO₂ (g) ⇌ H₂CO₃ (aq)

H₂O (aq) +  NH₃ (aq) ⇌ NH₄OH (aq) 

Which of the following statements is true?

Which species are Bronsted-Lowry acids in the reaction shown?

H₂PO₄⁻ (aq) + CN^- (aq) ⇌  HCN (aq)  + HPO₄²⁻ (aq)

Which of the following solutions will react with a strip magnesium ribbon?

Which substance reacts with ammonia but is not a Brønsted–Lowry acid?

Which of the following statements is incorrect about  0.01 mol dm^–3 CH₃COOH?

Two flasks contain two different acids labelled as HA and HB. A student measures the pH of each flask, and finds that they are pH 1 and pH 3 respectively. Which of the following statements is true?

Which of the following solutions will have the largest amount of H⁺ ions in moles?

If the pH of two acids, X and Y, are pH 1 and pH 2 respectively, which of the following is true?

1. X and Y could be strong or weak acids
2. The concentration of [H⁺] ions in X is higher than in Y
3. Acid X is stronger than acid Y

A student has two flasks containing 150 cm³ of nitric acid, HNO₃(aq) and ethanoic acid, CH₃COOH(aq). She writes the following three statements in her notebook about the acids. Which of them are correct?

1. HNO₃ dissociates more than CH₃COOH
2. HNO₃ conducts electricity better than CH₃COOH
3. more NaOH can be neutralized with HNO₃ than CH₃COOH

Which row shows the correct colours for two common indicators used in acid-alkali titrations?

In a titration, the equivalence point is reached when 23.70 cm³ of 0.02 mol dm^-3 potassium hydroxide reacts with 0.03 mol dm^-3 of sulfuric acid. What volume of acid is needed?

What is the number of moles of barium hydroxide in a 100 cm³ solution with a pH of 11 at 25 ℃?

(K_w = 1.00 x 10^-14 mol² dm^-6 at 298 K)

What is the pH of a solution made by adding 6.0 g of sodium hydroxide to 1 dm³ of water at 298K? (M_r NaOH = 40.00)

(K_w = 1.00 x 10^-14 mol² dm^-6 at 298 K)

Which values are correct for a solution that contains 0.056 g of KOH (M_r= 56) in 100 cm³ of water?

(K_w = 1.00 × 10^-14 mol² dm^-6 at 298 K)

Acid rain can be up to 50 times more acidic than normal rain, which has a pH around 5.5. What is the approximate concentration of H⁺ in acid rain?

Which is true about the hydrogensulfate ion, HSO₄^-, found in acid rain?

1. It is amphiprotic
2. It is amphoteric
3. Sulfur is in its highest oxidation state

Using appropriate molar ratios which mixtures could act as buffers?

I. NaOH and CH₃COOH

II. CH₃NH₂ and CH₃NH₃Cl

III. NH₃ and HCl

Which of the following salts would produce a solution with the highest pH if dissolved in water?

The acid–base indicator bromophenol blue changes colour from yellow to blue over a pH range of 3.0–4.6. Which statement is correct?

I. The pK_a is between 3.0 and 4.6

II. In a neutral solution [HIn] > [In^-]

III. It is a suitable indicator for a strong acid, weak base titration

A titration was carried out using 25.00 cm³ of 0.100 mol dm^-3 propanoic acid with 0.100 mol dm^-3 sodium hydroxide. The indicator phenolphthalein was used to determine the equivalence point. Phenolphthalein has a pH range of 8.3 to 10.0.  

If hydrochloric acid was used instead of propanoic acid of the same concentration, which of the following would remain the same? 

The table below shows data for the and values for some acids and bases at 298 K.

Which two formulas represent the weakest acid and the weakest base in the table?

The ionisation constant of water, K_w , at 40 °C is 2.92 x 10^-14. Which of the following statements is correct?

The K_b value for a base is 8.0 x 10^-4 at 298 K. What is the pK_a value for the conjugate acid at this temperature? 

The pKb value of HPO₄^2- is 6.8. What is its conjugate acid and what is the K_a value?

The strengths of four bases are:

• Phenylamine pK_{b =} 9.13
• Ethylamine K_b = 4.46 x 10^-4
• 3-Nitrophenol pK_b = 8.36
• Ethanol K_b = 3.16 x 10^-16

What is the order of increasing base strength?

The following reaction occurs between concentrated sulfuric and nitric acids.

H₂SO₄ + HNO₃ ⇋  H₂NO₃⁺ + HSO₄^-

Identify the two species which are acting as Brønsted–Lowry bases.

What role does each species play in the equilibrium below according to Brønsted-Lowry theory?

CH₃COOH + HCl  ⇌ CH₃COOH₂⁺ + Cl^-

Perbromic acid, HBrO₄ , is an example of a strong acid when dissolved in water. What is true about perbromic acid?

Potassium hydrogenphosphate has the formula K₂HPO₄ . What is the conjugate base of this compound?

For the equilibrium equation shown, which species are Brønsted-Lowry acids?

H₃NSO₃ (aq) + 2NH₃ (aq) ⇌ HNSO₃^2- (aq) + 2NH₄⁺ (aq)

Which would be formed when calcium oxide reacts with hydrochloric acid ?

 What is the sum of the coefficients when the following acid-base equation is balanced?

_HNO₃ (aq) + _Mg(HCO₃)₂ (s) →  _Mg(NO₃)₂ (aq) + _H₂O (l) + _CO₂  (g)

Which oxides react with calcium oxide?

1. SO₂
2. NO₂
3. K₂O

Which row correctly describes the reaction specified?

Determine which of the following solutions would be basic at 25 °C?

K_w = 1.0 × 10⁻¹⁴ mol² dm^-6

Calculate the pH of a solution of NaOH of concentration 0.001 mol dm^-3

Carbon dioxide reacts with water to form carbonic acid which can be represented in the following equation

CO₂(g)  +  H₂O(l)  ⇋  H⁺(aq)  +  HCO₃⁻(aq)

If the pressure is raised, what will happen to the position of equilibrium and the pH?

When comparing the separate reactions of 0.5 g magnesium metal with equal volumes and concentrations of hydrochloric acid and ethanoic acid you can say that the

A beaker contains 50 cm³ of sodium hydroxide solution and its pH is measured as 11.
If 450 cm³ of water is added to the beaker, what will be the new pH of the solution?

In the table below are the formulae of some acids and bases. Which row shows only weak acids and weak bases?

Three solutions of hydrochloric acid of different concentrations are shown below

X.   0.100 mol dm^-3

Y.   0.001 mol dm^-3

Z.   0.010 mol dm^-3

If these solutions are arranged from lowest to highest pH, then the order is  

Which of the following statements is correct? 

Which row shows the correct properties of 0.1 mol dm^-3 LiOH?

Equal volumes of hydrochloric acid of different concentrations are added to four beakers, A, B, C and D. Equal volumes of 1.0 mol dm^-3 sodium hydroxide are then added to the beakers and the pH is measured.

Which beaker contains the most concentrated solution of hydrochloric acid?

Which of the following statements are correct for a titration between 0.10 mol dm^-3 propanoic acid and 0.10 mol dm^-3 potassium hydroxide? 

Which of the following statements about indicators are correct? 

1.  The pK_a of the indicator is the midpoint of the pH range
2.  The colour of the indicator depends upon the pH of the solution
3.  At the end point of a titration [HIn] = [In^-]

Which statement about buffer solutions is not correct?

The pH range of four different indicators are:

Which indicator would be suitable for a titration involving hydrochloric acid and ammonia?

The table shows the pK_a and K_a values for four acids

Which of the following is the correct order of increasing strength of the acids

Which of the following statements is correct? 

Which of the following statements about conjugate acid and base pairs are correct?

What is the correct expression to use to determine the pH of butanoic acid with concentration of 0.75 mol dm^-3? 

The K_a of butanoic acid at 298 K is 1.51 x 10^-5 mol dm^-3

What is the correct expression for the base dissociation constant, K_b, for propylamine?