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Why does a powdered solid react faster with a dilute acid, at the same temperature, than a single lump of the same mass of the solid? A. Collisions between particles are more frequent. B. Collisions between particles are more energetic. C. The activation…
A student monitors the rate of a reaction using a colorimeter. In which mixture would the absorbance change as the reaction proceeds? A. NaOH(aq) + HNO3(aq) B. KCl(aq) + I2(aq) C. KI(aq) + Cl2(aq) D. CH3COOH(aq) + KOH(aq)
A reaction has an activation energy of 50 kJ mol−1 and an enthalpy change of −70 kJ mol−1. Which potential energy diagram represents this reaction? A. Graph A B. Graph B C. Graph C D. Graph D
At a certain temperature, Kc = 12 for the reaction What is the value of Kc, at the same temperature, for the reaction below? H2(g) + Br2(g) ⇌ 2 HBr(g) A. 122 B. 2 × 12 C. D.…
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
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+
Which 0.0050 mol dm−3 solution is most likely to have a pH of 12.0 at 298 K, where Kw = 1.00 × 10−14? A. Ba(OH)2(aq) B. NaOH(aq) C. NH3(aq) D. H2SO4(aq)
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− Kc = 3.2 × 10−7 A. NH3 B. H2O C. NH4+ D. OH−
In which species would nitrogen be oxidized if it were converted to N2O? A. NO2 B. NH4+ C. HNO3 D. N2O3