OAU Chemistry 2007/2007 Past Questions

All the following will liberate a gas when reacted with dilute hydrochloric acid except

The isomer of a compound C₅H₁₀ which does NOT decolorize bromine water is.

A mixture of nitrogen, oxygen and helium contains 0.25, 0.15 and 0.4mole of these gases respectively. If the pressure contribution due to oxygen was 2.5 atm. The partial pressure of helium is

Elements P has an atomic number of 12 while element Q has an atomic number 15. Combination of P and Q gave a compound P_mQ_n. the respective values of m and n are

C_xH_y + 90₂ → 6CO₂ + 6H₂O. The hydrocarbon, C_xH_y, in the reaction above is most likely

A 512cm³ sample of a gas weighed 1.236g at 20°C and a pressure of one atmosphere. The relative molecular mass of the gas is [R = 8.314K^-1mol^-1; 1 atm = 101,325Jm^-3]

The amount of methane molecules, CH₄, in 8.0 grams of methane is

The concentration of a solution obtained by dissolving 0.53g of pure anhydrous Na₂CO₃ in water to make 250cm³ of solution is

What is the maximum volume of CO2 at s.t.p. that can be obtained when dilute hydrochloric acid is added to l0grarns of CaCO3?[Ca = 40, C = 12, 0 = 16]

Sulphur (IV) oxide travels a given distance in 10 sec. How long will it take equal volume of helium to travel the same distance under the same conditions? [S = 32, 0 = 16, He = 4]

The volume of hydrogen gas produced at S.T.P. when 100ml of 2M hydrochloric acid reacts with excess zinc is:

During electrolysis, two cells each containing molten Al2O3 and fuse CaCl2 were connected in series. A current of 15 Amp was passed through the cells for a given period of time. At the end of the electrolysis 9g of calcium was found to have been deposited at the cathode. What mass of aluminum would be deposited in the second cell. [A = 27, Ca = 40]

The balanced equation for the reaction of tin(II) salt with potassium heptaoxodichloromate (VI) in an acidic medium can be represented as Sn²⁺ + fCr₂O^2-₇ + gH⁺ → hSn⁴⁺ + iCr³⁺ + jH₂O. e, f, g, i and j respectively are

The pH of a solution containing 0.5 x 10^-6M H₂SO₄ is

Which of the following oxides will NOT dissolve in both dilute hydrochloric acid and 2M sodium hydroxide solution?

The I.U.P.A.C. name for the compound is

Metal salt of long chain fatty acids are known as

The compound
$\table , , O, , , , , ; , , ∣∣ , , , , , ; CH_3, -, C, -, O, -, CH_2CH_2CH_3$
, when refluxed with dilute HCI, is hydrolysed to give

The compound
$\table ,,,,O,;,,,,∣∣,;CH_3,-,CH_2,-,C,-,CH_3$
is the product of oxidation of

The curve above represent the solubility curve of KCLO₃.the number of moles KLOO₃ crystals produced by cooling 200cm³ of a suturated solution of the salt from 65^oc to 25^oc is

During a compression process involving an idea gas of pressure P₁,when the volume,V₁ of the gas was halved, the temperature in kelvin increased by half its initial value.The final pressure P₂ is given by

Cellulose and starch can be classified as one of the following