2012 OAU Chemistry Post-UTME

During the electrolysis of dilute tetraoxosulphate (VI) acid solution, 0.05 mole of electrons were passed. What volume of gas was produced at the anode?

What volume of 0.750moldm^-3 Na₂CO₃ solution could be diluted to 250cm³ to reduce concentration of 0.025moldm^-3

The reaction, Y → Product is of first order with the initial concentration of

Y = 3.55 x 10^-3 moldm^-3 and the rate constant of 5.25 x10^-3 moldm^-3

What is the half-reaction

Given the half-cell reaction, 2Br → Br₂ how many moles of electron will be required to produce 0.56dm³ of bromine at s.t.p.? [molar volume of gas at s.t.p 22.4 dm³]

The equilibrium constant, Kc for the reaction

${\mathrm{NO}}_{\left(\mathrm{g}\right) }+ \frac{1}{2}{\mathrm{O}}_{2\left(\mathrm{g}\right)} \to {\mathrm{NO}}_{2\left(\mathrm{g}\right)}, \mathrm{is} 35.2$

What is the value of K for the reaction

${\mathrm{NO}}_{2\left(\mathrm{g}\right)}\to {\mathrm{NO}}_{\left(\mathrm{g}\right) }+ \frac{1}{2}{\mathrm{O}}_{2\left(\mathrm{g}\right)}$

An atom has a core and outside the core an electron occupies an orbital for which the principal quantum number

n = 4, L = 0, m = 0, and s = +¹/₂ and –¹/₂

The atom is likely to be

$$\begin{gathered} \mathrm{An} \mathrm{element} \mathrm{B}, \mathrm{has} \mathrm{two} \mathrm{isotopes} \\ {\mathrm{B}}_{10}^{20} \mathrm{and} {\mathrm{B}}_{10}^{22} \mathrm{present} \mathrm{in} \mathrm{ratio} 2:3 \\ \mathrm{The} \mathrm{relative} \mathrm{atomic} \mathrm{mass} \mathrm{of} \mathrm{B} \mathrm{is} \end{gathered}$$

What quantity of current is required to deposit 2.4g of copper in a period of 750 seconds during an electrolytic deposition process? [Cu 64, IF = 96500C mol^-1]

Platinum electrodes are dipped into copper sulphate solution in a voltameter. The solution left after electrolysis is

What volume of water is produced when a mixture of 150cm³ of hydrogen and 100cm³ of oxygen is exploded in a eudiometer?

A chloroform solution of pure organic compound was spotted at a distance of 0.80cm from the base of a 20cm long chromatoplate. If the compound has the rf-value of 0.505 and moves halfway up the 20cm long plate, which is the distance of the solvent front from the top of the plate upon elution?

The main organic product named when bromine water is added to but-1-ene is

The standard reduction potentials for the following half-cell reactions are,

$$\begin{gathered} 2{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)}\to {\mathrm{O}}_{2\left(\mathrm{g}\right)}+ 4{\mathrm{H}}_{\left(\mathrm{aq}\right)}^{+}+4{\mathrm{E}}^0=1.23\mathrm{V} \\ 2{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)}\to 2{\mathrm{O}}_{2\left(\mathrm{g}\right)}+ 4{\mathrm{H}}_{\left(\mathrm{aq}\right)}^{+}+4{\mathrm{E}}^0=–0.68\mathrm{V} \end{gathered}$$

Bonding in ammonium chloride is

Valence shell electron pair theory through hybridization predicts that boron trichloride is

The basic tenet of valence bond electron pair repulsion theory is that the pairs of electrons making the sigma bonds dictate the shape of molecules. The pi-bonds often encounter in some molecules serve to

A chemical equilibrium is established when

Oxygen is extracted from water by

Excess ethanol was soarked with 3g of pure oxygen in a combustion chamber. How many molecules of CO₂ are produced? [N = 6.02 × 10²³ molecules mol⁻¹]

The energy for the dissociation of molecule AB in kJ in the diagram of energy against the reaction coordinate shown below is: