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The following data were obtained at constant temperature for the reaction 2 NO(g) + Br2(g) → 2 NOBr(g). What rate equation can be deduced from the data? A. Rate = k[NO][Br2] B. Rate = k[NO]2[Br2] C.…
The Arrhenius equation relates the rate constant, k, of a reaction to the absolute temperature, T. Which graph gives a straight line with a gradient equal to −Ea/R? A. k against 1/T B. ln k against T C. ln k against 1/T D.…
For the reaction N2(g) + 3 H2(g) ⇌ 2 NH3(g) at a certain temperature, the equilibrium concentrations, in mol dm−3, are: [N2] = 0.10, [H2] = 0.20, [NH3] = 0.40 What is the value of Kc? A. 0.0050 B. 8.0 C.…
Iron(III) ions and thiocyanate ions react to form a blood-red complex ion. Fe3+(aq) + SCN−(aq) ⇌ [FeSCN]2+(aq) Which of these changes would shift the equilibrium to the right? I. Addition of solid potassium thiocyanate, KSCN II. Addition of…
Equal volumes of 0.050 mol dm−3 ethanoic acid and 0.050 mol dm−3 hydrochloric acid are each titrated with 0.050 mol dm−3 sodium hydroxide solution. Which quantity is the same for the two titrations? A. Initial pH…
Which acid has the weakest conjugate base? A. HF B. CH3COOH C. HNO3 D. NH4+
Which pair of solutions will form a buffer when mixed? A. 25 cm3 of 0.20 mol dm−3 HCl and 25 cm3 of 0.20 mol dm−3 NaOH B. 25 cm3 of 0.20 mol dm−3 NH3…
Which species can act as a Lewis base but not as a Lewis acid? A. BF3 B. Fe3+ C. NH3 D. H+
A voltaic cell is based on the reaction Zn(s) + Ni2+(aq) → Zn2+(aq) + Ni(s) The half-cells are connected by a salt bridge containing aqueous potassium nitrate. What happens when the cell operates? A. Electrons flow from Ni to Zn; anions in the…
What is the value of c when the equation below is balanced using the smallest whole numbers? a Cu(s) + b NO3−(aq) + c H+(aq) → d Cu2+(aq) + e NO2(g) + f H2O(l) A. 2 B. 3 C. 4 D. 6