OAU Chemistry 2014/2015 Past Questions

A motor truck releases an average of 5.0g CO into air for every km covered. How many molecules of CO will be emitted into the air if the truck travels 8km? [C = 12; 0 = 16; N_A = 6.02 x 10^2]

A sample of an organic compound was weighed to be 0.250g and subjected to Kjeldahl treatment. The ammonia produced was neutralized by 27.0cm³ of 0.100 moldm³ HCl. What is the percentage of nitrogen in the compound? [H = 1; N = 14]

Given the half-redox reaction$ O_2 + 4H^{+} + 4e^{-} ⟶ 2H_{2}O$, how many moles of electron will be required to produce 3.0 x 10²² molecules of water?

The quantum number I in an atom defines

The hybridization of the central atom in a molecule

Lithium with atomic number of 3 is a

The correct name for $HCOOC_2H_5$ is

When CaC₂ reacts with water, the organic product forms is

100 cm³ of ethyne was mixed with 240 cm of oxygen in a combustion chamber. What volume of carbon (iv)oxide is produced?

Uranium-235 explodes when bombarded with a slow moving neutron according to the equation below:
²³⁵₉₂U + ¹₀n → ⁹⁴₃₆Kr + Ba + 3¹₀n
The atomic number and mass of Ba respectively are

The reduction potential of two electrodes are
X²⁺ + 2e^- → X, E° = 0.042 v
Y⁺ + e^- → Y, E° = 0.012v

A sample of water weighs 200.00g at 298K. What is the volume of this quantity of water in cubic meters given that the density of water at 298,K is 0.98gcm^-3?

What is the pH of 500 cm^3 of 0.02 moldm^-3 tetreoxosulphur (VI) acid?

The main product of electrophilic addition of HCl to 2 methylpropene is

Which of the following compounds would you expect to show positive iodoform test? (i) Batanone (ii) Propanoic acid (iii) Ethanol (iv) Benzaldehy de (v) But-2-one .

The complete combustion of one mole of an alkanol is shown below. C_n2n+1CHO + XO₂ → yCO₂ + 2H₂O What is the value of x in terms of n?

An ion has a charge of +3. The nucleus of the ion has a mass of 120. The number of neutrons in the nucleus is 1.50 times that of the number of proton, How many electrons are in the ion?

Consider the following reactions (i) LiOH + CO_2 ⟶ Li2CO3 + H2O (ii) 2H2 + O2 ⟶ 2H2O (iii) 2Cu + O2 ⟶ 2CuO (iv) HCl + AgNO3 ⟶ AgCl + HNO3 Which of these reactions are redox reactions?

Which of the following metals cannot displace hydrogen from steam?

Consider the exothermic reaction [INSERT EQUATION] If the temperature of the reaction is reduced from 600°C to 300°C and no other change take place then,

The molarity of 5% by weight of aqueous solution of tetraoxosulphate(VI) acid [molecular weight 98] is