OAU Chemistry 2012/2013 Past Questions

Which of the following is composed of the element, H, O, Al, and Si?

Which of the following is not a chemical reaction?

What condition favours the formation of the product for the endothermic reaction, N2O4(g) ⟷ 2NO2(g)?

What is the percentage yield of water if 0.90g of water is obtained when 29.0g of butane is burned in excess oxygen?

The order of reactivity of five metals is P>Q>R>S> T. Which of the following reactions can occur spontaneously?

An element Y has the electronic configuration of 1s² 2s² 2p⁶ 3s² 3p³.

Which of the following is NOT implicated as a major cause of global warming?

Which of the following shows little or no net reaction when the volume of the system is decreased?

A solution of 0.20 mole of NaBr and 0.20 mole of MgBr₂ in 2.0 dm³ of water is to be analysed. How many moles of Pb(NO₃)₂ must be added to precipitate all the bromide as insoluble PbBr₂?

A given volume of methane diffuses in 20s. How long will it take the same volume of sulphur (IV) oxide to diffuse under the same conditions? [C = 12, H = 1, S = 32, O = 16]

The reaction, A + B → C, can be represented by the equation, r = k[A][B], k in this equation is,

The reaction that takes places in Daniel cell is,

100.0g of KClO3 was added to$ 40.0cm^3$ of water to give a saturated solution at 298K. If the solubility of the salt is $20.0 moldm^-3 $at 298K, what percentage of the salt is left undisolved? [K = 39, Cl = 35.5, 0 = 16]

A tertiary amine is

An electron described by the quantum number, n = 4, l = 3 can be located in what orbital?

An aqueous solution of a crystalline salt reacts with dilute HCl to give a yellow precipitate and a gas that turned dichloromate paper green. The crystalline salt may be,

The oxidation states of nitrogen in ammonium nitrate are,

Which of these reagents can confirm the presence of a triple bond?

²²⁶₈₈Ra → ^x₈₆Rn + α What is the value of x in the nuclear reaction?

In the electrolysis of copper (II) sulphate using copper electrodes, the processes that occur at the anode and cathode respectively are,

Which of the following statements is true when sulphur atom forms its ion?

An excess 0.10moldm^-3 HCl was poured into a big beaker containing 2g of limestone. The unreacted acid required 25cm³ of 0.10moldm^-3 potassium carbonate to neutralize it. What was the original volume of the acid? [Ca = 40, C = 12, 0 = 16]