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The equilibrium constant, Kc, for the reaction A + 2 B ⇌ 3 C + D has a value of 3.0 at a certain temperature. What is the value of Kc for the reaction below at the same temperature? 6 C + 2 D ⇌ 2 A + 4 B A. 0.11 B. 0.33 C. 1.5 D. 9.0
The following equilibrium is established at a certain temperature. At equilibrium, [N2] = 0.40 mol dm−3 and [O2] = 0.10 mol dm−3. What is the…
A closed flask is filled with 1.0 mol of carbon monoxide and 1.0 mol of steam, and the mixture reaches equilibrium according to the equation below. CO(g) + H2O(g) ⇌ CO2(g) + H2(g) At equilibrium the flask holds 0.75 mol of CO2. What is…
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+
What happens to the amount of hydrogen ions and to the hydrogen ion concentration when water is added to a solution of ethanoic acid, CH3COOH(aq)? A. n(H+) decreases; [H+] decreases B. n(H+) increases; [H+] decreases C.…
Which 0.10 mol dm−3 aqueous solution has the lowest pH? A. CH3COOH B. HCl C. H2SO4 D. NH4Cl
What is the strongest base in the equilibrium below? NH3 + H2O ⇌ NH4+ + OH− Kb = 1.8 × 10−5 A. NH3 B. H2O C. NH4+ D. OH−
Boron trifluoride reacts with ammonia as shown. BF3 + NH3 → F3B−NH3 Which statement is correct? A. NH3 is a Lewis acid because it donates a pair of electrons B. BF3 is a Lewis base because it donates a pair of electrons C. NH3 is a…
A weak acid is titrated with sodium hydroxide solution. Which value of pKa can be estimated from this titration curve? A. 8.4 B. 4.2 C. 2.6 D. 12.3
Equimolar aqueous solutions of four salts are prepared. In which set are the salts arranged in order of increasing pH? A. KCl < NH4Cl < CH3COOK < Na2CO3 B. NH4Cl < KCl < Na2CO3 < CH3COOK C.…