Zadanie 31
Two acid-base equilibria are shown. Equation 1: HCN(aq) + H2O(l) ⇌ CN−(aq) + H3O+(aq) Equation 2: NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH−(aq) Which option correctly describes the role of water in each forward reaction? A. In equation 1 water…
Brønsted-Lowry acids and bases
Define a Brønsted-Lowry acid as a proton donor and a base as a proton acceptor, and identify which species donates and which accepts a proton in a given acid-base equation, including reactions of ammonia and water.
Tę umiejętność sprawdza 17 zadań wzorowanych na arkuszach IB z lat 2022–2026.
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Zadanie 38
In the nitration of benzene, the electrophile NO2+ is produced by the reaction of concentrated nitric acid with concentrated sulfuric acid. HNO3 + 2 H2SO4 → NO2+ + H3O+ + 2 HSO4− Which statement describes the role of sulfuric acid in this…
Zadanie 1c
Cresolphthalein is manufactured from 2-methylphenol, CH3C6H4OH. State an equation that shows 2-methylphenol acting as a Brønsted–Lowry acid.
- Materiał graficzny
Zadanie 4a
The structure of galantamine is shown below. (i) State the name of the functional group that contains the nitrogen atom. (ii) Outline the effect of this functional group on the pH of water in which galantamine is dissolved, giving the direction of the change…
- Materiał graficzny
Zadanie 32
In which reaction does water behave as a Brønsted–Lowry acid? A. H2O(l) + HCl(g) → H3O+(aq) + Cl−(aq) B. H2O(g) + SO3(g) → H2SO4(l) C. 2 H2O(l) → 2 H2(g) + O2(g) D. H2O(l) + NH3(aq) → NH4+(aq) + OH−(aq)
Zadanie 32
Which reactions involve the transfer of a proton? I. CH3COOH(aq) + NH3(aq) → CH3COONH4(aq) II. 2 CH3COOH(aq) + Mg(s) → (CH3COO)2Mg(aq) + H2(g) III. CH3COOH(aq) + NaHCO3(s) → CH3COONa(aq) + H2O(l) + CO2(g) A. I and II only B. I and III…
Zadanie 37
Which term cannot describe the chloride ion, Cl−? A. Lewis base B. ligand C. Brønsted–Lowry acid D. nucleophile
Zadanie 1b
The structure of a tartaric acid molecule is shown. (i) State how many hydrogen atoms in a tartaric acid molecule are acidic. (ii) Deduce the structural formula of the conjugate base of tartaric acid. (iii) Predict, giving a reason, whether tartaric acid is a…
- Materiał graficzny
Zadanie 6c
The complex ion [Cr(H2O)6]3+ is violet and absorbs light most strongly at about 580 nm. The complex ion [Cr(NH3)6]3+ is orange and absorbs light most strongly at about 465 nm. (i) Explain why the two complex ions have different colours. Use…
Zadanie 1a
(i) Deduce the ionic equation, including state symbols, for the reaction of hydrogen bromide gas with water. (ii) Calculate the pH of 0.25 mol dm−3 hydrobromic acid. (iii) Explain why a solution of methanoic acid has a higher pH than…
Zadanie 2a
Calcium hydride, CaH2, is an ionic compound that forms a crystalline lattice of Ca2+ and H− ions. Deduce whether calcium hydride behaves as a Brønsted–Lowry acid or as a Brønsted–Lowry base, and justify your answer.
Zadanie 2a
Lithium hydride, LiH, forms a crystalline ionic lattice made of Li+ and H− ions. Deduce, giving a reason, whether lithium hydride could be classified as a Brønsted–Lowry acid or as a Brønsted–Lowry base.
Zadanie 1d
The presence of calcium nitride in the product can be demonstrated by adding water. The nitride is hydrolysed to form calcium hydroxide and ammonia. (i) Calculate coefficients that balance the equation for the reaction: __ Ca3N2(s) + __ H2O(l) →…
Zadanie 6d
(i) Methanal can be reduced. State the name of the organic product formed. (ii) Methanal can also be oxidized to methanoic acid, HCOOH, which is a weak Brønsted–Lowry acid. State the meaning of the term weak Brønsted–Lowry acid.
Zadanie 24
Which species are Brønsted–Lowry acids in the equilibrium below? HCO3−(aq) + H2O(l) ⇌ H3O+(aq) + CO32−(aq) A. HCO3− and H2O B. H2O and CO32− C. H3O+ and CO32− D. HCO3− and H3O+
Zadanie 27
Which of these species can act as both a Lewis base and a Brønsted–Lowry base? I. CH3NH2 II. BF3 III. H2O A. I and II only B. I and III only C. II and III only D. I, II and III
Zadanie 1b
State, with a reason, whether the ammonium ion acts as a Brønsted–Lowry acid or base when it reacts with water to form ammonia.