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Marble chips react with dilute hydrochloric acid. Which combination of changes would decrease the rate of reaction? A. Concentration of acid increased; marble chips replaced by larger chips B. Concentration of acid decreased; marble chips replaced by larger…
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+
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…
Which species is the reducing agent in the reaction below? Cr2O72−(aq) + 14 H+(aq) + 6 Fe2+(aq) → 2 Cr3+(aq) + 6 Fe3+(aq) + 7 H2O(l) A. Cr2O72− B. H+ C. H2O D. Fe2+
Molten lead(II) bromide is electrolysed using inert graphite electrodes connected to a DC power supply. Bromine forms at one of the electrodes. Which row is correct for the electrode where bromine forms? A. Anode; positive electrode; electrons leave this…
Which of the structures I, II and III are structural isomers of C4H8? A. I and II only B. I and III only C. II and III only D. I, II and III
Which homologous series has the general formula CnH2nO2? A. Alcohols B. Aldehydes C. Ethers D. Carboxylic acids
Which conditions best favour the oxidation of butan-1-ol to butanal rather than to butanoic acid? A. Excess oxidizing agent, heated under reflux B. Excess oxidizing agent, heated with the product distilled off as it forms C. Limited oxidizing agent, heated…
The cyanide ion, CN−, acts as a nucleophile. With which compound is it most likely to react? A. 1-bromopropane B. Propene C. Benzene D. Propane