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Which option describes the 1H NMR spectrum of the compound shown? A. 2 signals, relative areas 3:5 B. 3 signals, relative areas 3:4:1 C. 5 signals, relative areas 3:2:1:1:1 D. 4 signals, relative areas 3:2:2:1
Which classification is correct for this reaction? 2 Mg(s) + CO2(g) → 2 MgO(s) + C(s), heat is released A. Endothermic; temperature decreases; reactants more stable B. Exothermic; temperature decreases; products more stable C. Exothermic; temperature…
Which of the following processes are exothermic? I. K(g) → K+(g) + e− II. H2O(g) → H2O(l) III. Ag+(g) + Cl−(g) → AgCl(s) A. I and II only B. I and III only C. II and III only D. I, II and III
The diagram shows the energy profile of a reaction. Which expression could give the enthalpy change, ΔH, of this reaction in kJ mol−1? A. +87 − 215 B. −215 + 87 C. +215 − 87 D. −215 − 87
What is the sum of the coefficients when this equation is balanced with the smallest whole numbers? A. 20 B. 37 C. 47 D. 53
Ethane burns in a limited supply of oxygen. Which product is formed by incomplete combustion but not by complete combustion? A. CO2 B. CO C. H2O D. SO2
Which option describes the electrode reactions in a hydrogen fuel cell with an acidic electrolyte? 2 H2(g) + O2(g) → 2 H2O(l) A. Cathode: hydrogen is oxidized; anode: oxygen is reduced B. Cathode: oxygen is reduced; anode: hydrogen is oxidized C.…
Given the following data: CaO(s) + CO2(g) → CaCO3(s) ΔH = −p kJ 2 Ca(s) + O2(g) → 2 CaO(s) ΔH = −q kJ 2 CaCO3(s) → 2 Ca(s) + 2 C(s) + 3 O2(g) ΔH = +r kJ What is the ΔH of the…
What are the electron domain geometry and the molecular geometry of sulfur hexafluoride, SF6? In each option the electron domain geometry is given first and the molecular geometry second. A. Octahedral, octahedral B. Octahedral, square planar C.…
Which of these changes has the largest negative standard enthalpy change, ΔH⊖? A. Na+(g) + Cl−(g) → NaCl(s) B. SrO(s) → Sr2+(g) + O2−(g) C. Ca2+(g) + 2 Cl−(g) → CaCl2(s) D. Mg2+(g) + O2−(g) → MgO(s)