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An aqueous solution of nickel(II) sulfate, which contains the [Ni(H2O)6]2+ ion, is green. Which statement explains the origin of this colour? A. Red light is absorbed when electrons are promoted between the split d orbitals of the nickel ion. B. Red…
A fixed amount of an ideal gas is kept at constant temperature while the volume of its container is decreased by 60 %. How does the pressure of the gas change? pV = nRT A. Pressure decreases by 60 % B. Pressure increases by 60 % C. Pressure increases by 150…
Which compound shows cis-trans isomerism? A. Compound A B. Compound B C. CH2=C(CH3)2 D. CH3CH=CH2
Which two functional groups occur in both molecule P and molecule Q? A. Amino and a benzene ring B. Hydroxyl and ester C. Hydroxyl and a benzene ring D. Amino and hydroxyl
Vanadium forms compounds in the +2, +3, +4 and +5 oxidation states. Which statement explains why vanadium shows a range of oxidation states? A. The 3d sublevel splits into two sets of orbitals of different energy in its complexes B. The 3d and 4s electrons…
The energy profile below was recorded for a reaction. Which pair of statements is consistent with it? In each option the first statement compares the enthalpy of the products with that of the reactants and the second gives the sign of ΔH. A. products…
The NMR spectrum of an alcohol with molecular formula C5H11OH shows four signals with relative areas 6 : 4 : 1 : 1. Which alcohol is it? A. Pentan-1-ol B. Pentan-3-ol C. 2-methylbutan-2-ol D. 2,2-dimethylpropan-1-ol
Which oxygen-containing compound gives this low-resolution NMR spectrum? A. Propanone B. Methyl ethanoate C. Propanoic acid D. Propan-2-ol
A liquid fuel was burned in a spirit burner and the heat released was used to warm water in a metal calorimeter, as shown. Q = mcΔT What is the standard enthalpy change of combustion, ΔHcombustion⊖, of the fuel according to the…
How many chiral centres does the molecule shown contain? A. 1 B. 2 C. 3 D. 4