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In a kinetics experiment, excess dilute hydrochloric acid was added to a fixed mass of marble chips (calcium carbonate), and the volume of carbon dioxide gas produced was measured over time. What is the average rate of gas production for the first 20 seconds?…
The container holding the equilibrium mixture below is compressed to half its volume while the temperature is kept constant. Which row gives the change in the amount of PCl5 and the effect on the equilibrium constant, K?…
What are the electron domain geometries around the nitrogen atom and the carbon atom bonded directly to it, in alanine, H2NCH(CH3)COOH? A. Trigonal planar (C), trigonal pyramidal (N) B. Tetrahedral (C), trigonal pyramidal (N) C. Trigonal pyramidal (C),…
A sealed, rigid container holds the following gas-phase reaction at equilibrium. N2(g) + O2(g) ⇌ 2 NO(g) ΔH⊖ = +180 kJ mol−1 Which pair of changes would move the equilibrium position furthest towards the products? A.…
What is the conjugate acid of the hydrogen phosphate ion, HPO42−? A. PO43− B. H2PO4− C. H3PO4 D. HPO32−
What is the pH of a 0.020 mol dm−3 solution of nitric acid, HNO3(aq)? A. 1.0 B. 1.7 C. 2.0 D. 12.3
Which two species can act both as Brønsted–Lowry acids and as Brønsted–Lowry bases? A. H2CO3 and CO32− B. HCO3− and SO32− C. HCO3− and HSO3− D. H2SO3 and HSO3−
Which solution has a pH of 11.0 at 298 K? A. 10−3 mol dm−3 KOH(aq) B. 10−11 mol dm−3 KOH(aq) C. 10−3 mol dm−3 NH3(aq) D. 10−3 mol dm−3 HCl(aq)
Which of these solutions has a pH greater than 7 at 25 °C? A. [H+] = 1.0 × 10−5 mol dm−3 B. [OH−] = 1.0 × 10−10 mol dm−3 C. [H3O+] = 1.0 × 10−11 mol dm−3 D.…
The pH of a solution is measured as 4.0. Which value, in mol dm−3, is the hydrogen-ion concentration, [H+], of this solution? A. 4.0 × 10−4 B. 1.0 × 10−4 C. 1.0 × 104 D. 4.0 × 104