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In the nitration of benzene, the electrophile NO2+ is produced by the reaction of concentrated nitric acid with concentrated sulfuric acid. HNO3 + 2 H2SO4 → NO2+ + H3O+ + 2 HSO4− Which statement describes the role of sulfuric acid in this…
Which reaction will be fastest when a halogen is substituted by aqueous hydroxide ions? A. (CH3)2C(F)CH2CH2CH3 B. (CH3)2C(Cl)CH2CH2CH3 C. (CH3)2C(Br)CH2CH2CH3 D. (CH3)2C(I)CH2CH2CH3
What occurs during the operation of a galvanic cell containing zinc, Zn, and nickel, Ni? Zn(s) ∣ Zn2+(aq) ∣∣ Ni2+(aq) ∣ Ni(s) I. Zinc atoms are oxidized at the anode II. Electrons flow through the external circuit from the nickel electrode to the zinc…
Which statements about the reaction of hydrogen bromide with 2-methylpropene are correct? I. A tertiary carbocation is formed as an intermediate. II. The major product is a primary halogenoalkane. III. The first step of the mechanism is attack of an…
What is the charge on this complex ion of chromium(III), [Cr(H2O)4Cl2]×? A. 1+ B. 3+ C. 5+ D. 1-
An electrochemical cell is written in cell notation with its standard cell potential. Pb(s) ∣ Pb2+(aq) ∣∣ Mg2+(aq) ∣ Mg(s) Ecell⊖ = −2.24 V What is correct about the cell reaction as written? In each option the sign of…
Which of these reactions are nucleophilic substitutions? I. OH− + CH3CH2CH2Cl → CH3CH=CH2 + H2O + Cl− II. I− + CH3CH2Br → CH3CH2I + Br− III. CH3O− + CH3CH2Cl → CH3CH2OCH3 + Cl− A. I and II only B. I and III only C. II and III only D. I,…
A beam containing protons, neutrons and electrons is passed between two charged metal plates. The three paths observed are labelled P, Q and R. Which row correctly identifies the particle following each path? A. P: electron, Q: proton, R: neutron B. P: proton,…
Determine the mass of sodium thiosulfate pentahydrate, Na2S2O3 ⋅ 5 H2O, needed to prepare 250.0 cm3 of a 0.2000 mol dm−3 solution.
Explain how the 0.2000 mol dm−3 solution is prepared in a volumetric flask from the weighed solid.