UTME CBT FREE Practice Test – Chemistry

The reaction represented by the equation above is useful in the production of _______

A. propanol    B. butanol    C. methanol    D. ethanol

A compound that gives a brick-red colour to a non-luminous flame is likely to contain

A. copper ions.   B. sodium ions.   C. calcium ions.   D. aluminium ions.

Potassium trioxochlorate(V) has a solubility of 1.5 mol dm^-3 at 45^oC. On cooling this solution to a temperature of 20^oC, the solubility was found to be 0.5 mol dm^-3. What mass of KCIO₃ was
crystalized out? [K = 39, Cl = 35.5, O = 16]

A. 1.00g.     B. 1000g.    C. 12.25 g.     D. 122.50 g.

A gas jar was inverted over burning yellow phosphorus floating over water in a beaker. After burning, the water level was found to rise in the gas jar. The water level rises because _____ 

A. pressure inside the gas jar is greater than pressure outside it
B. the air in the gas jar had been used up by burning
C. oxygen in the gas jar had been used up by burning
D. nitrogen in the gas jar had been used up by burning

An element X forms the following compounds with chlorine: XCl₄, XCl₃, XCl₂. This illustrates the ________

A. law of multiple proportions
B. law of chemical proportions
C. law of simple proportions
D. law of conservation of mass

How many isomers has C₃H₆Cl₂?

A. 2     B. 3     C. 4     D. 5

Bronze is a mixture of _______

A. Cu and Mg.    B. Cu and Sn.    C. Cu and Zn.    D. Cu and Pb.

Consider the reaction represented by the equation: N₂O_4(g) ↔ 2NO_2(g); = +x kJmol^-1

What happens when the temperature is reduced at equilibrium?

A. Concentration of N₂O_4(g) decreases.
B. Concentration of N₂O_4(g) increases.
C. Pressure exerted by the gases increases.
D. Pressure exerted by the gases remains constant.

Which of the following salts will turn blue litmus red?

A. Sodium tetrahydroxozincate(II).
B. Potassium hydrogentetraoxosulphate(Vl).
C. Sodium trioxocarbonate(IV).
D. Zinc chloride hydroxide.

A chemical reaction with entropy change of 20 JK^-1 and free energy change +55000 J occurred at -23^oC. Calculate the enthalpy change

(a) 55 460 J    (b) 44 540 J    (c) 50000 J    (d) 60 000 J

Which of the following gases are arranged in increasing order of diffusion rate? [H = 1.0; C = 12; N = 14; O = 16; S =32]

A. SO₂, O_2, NH₃, H₂.      B. H₂S, NH₂, O₂, SO₂.      C. CO₂ , N₂O, O₂ SO₂.      D. NH₃, NO₂, N₂, CO₂.

In the diagram above, X is the ______

A. enthalpy    B. enthalpy change    C. activation energy    D. activated complex.

Hardness of water is mainly due to the presence of ______

A. calcium hydroxide or magnesium hydroxide
B. calcium trioxocarbonate (IV) or calcium tetraoxosuiphate (VI)
C. sodium hydroxide or magnesium hydroxide
D. calcium chloride or sodium chloride salts.

A hydrocarbon has an empirical formula CH and a vapour density of 39. Determine its molecular formula. [C=12, H=1]

A. C₂H₆    B. C₃H₆   C. C₃H₄   D. C₆H₆

A hydrogen atom which has lost an electron contains

A. one proton only
B. one neutron only
C. one proton and one neutron
D. one proton, one electron and one neutron.

In the redox reaction 2Fe²⁺ + Cl₂ → 2Fe³⁺ + 2Cl^-  

A. Cl₂ is reduced because it has lost electrons
B. Cl₂ is reduced because its oxidation number has decreased
C. Cl₂ is reduced because its molecule is changed to two ions
D. Fe²⁺ is reduced because it has lost electrons

A property common to the structure above is that they have the same

(a) structural and molecular formulae
(b) structural formula but different molecular formulae
(c) number of carbon but different molecular mass
(d) molecular formula but different structural formula

The molecular lattice of iodine is held together by _______

A. dative bond     B. metallic bond    C. hydrogen bond    D. van der Waal’s forces.

Which of the following substances are all made by the process of polymerization?

A. Nylon and soap.
B. Ethanoic acid, margarine and ethanol
C. Nylon and artificial rubber
D. Soap and butane

An effect of thermal pollution on water bodies is that the ______

A. volume of water reduces
B. volume of chemical waste increases
C.. level of oxides of nitrogen increases
D. level of oxygen reduces.

Bronze is preferred to copper in the making of medals because it ______

A. is stronger    B. can withstand low temperature     C. is lighter     D. has low tensile strength.

Given that M is the mass of a substance deposited during electrolysis and Q is the quantity of electricity consumed, then Faraday’s first law can be written as _________

Consider the reaction represented by the following equation: C₂H₂ +yH₂ → C₂H₆

The value of y in the reaction is

A. 4.    B. 3.    C. 2.    D. 1.

Which of the following factors that affect the rate of chemical reactions can be explained in terms of the collision theory?

I. Concentration    II. Pressure    III. Temperature    IV. Catalyst.

A. I and II only    B. I, II and III only    C. I and III only    D. I, III and IV only.

Fluorine does not occur in the free state in nature because

A. it is a poisonous gas.   B. it belongs to the halogen family.   C. it is inert.   D. of its high reactivity.

The function of zinc electrode in a galvanic cell is that it _______

A. undergoes reduction
B. serves as the positive electrode
C. produces electrons
D. uses up electrons.

A hydrocarbon compound contains 92.3% carbon. Determine its empirical formula. [H = 1.00; C = 12.0]

A. CH.     B. CH₂.     C. CH₃.     D. C₂H₃.

Which of the following contains two amphoteric oxides?  

A. Sodium oxide Zinc oxide, Magnesium oxide
B. Aluminium oxide, Calcium oxide, Zinc oxide
C. Potassium oxide, Lithium oxide, Carbon dioxide
D. Silver oxide, Lead oxide, Sodium oxide

12 g of solid potassium chlorate (KCIO₃) were added to 40 g of water and heated to dissolve all the solid. As the solution cools, crystals of potassium chlorate started forming at 66°C. The solubility of potassium chlorate at 66°C is therefore _____

A. 66    B. 33    C. 30    D. 20

The gas law which describes the relationship between volume and temperature is

A. Boyle’s law.    B. Charles’ law.    C. Dalton’s law.    D. Graham’s law.

If the difference in electronegativity of elements P and Q is 3.0. The bond that will be formed between them is _______

A. metallic.     B. covalent.    C. co-ordinate.    D. ionic.

Which of the following will produce a solution with pH less than 7 at equivalent point?

A. HNO₃ + NaOH.    B. H₂SO₄ + KOH.    C. HCI + Mg(OH)₂.    D. HNO + KOH.

The highest rate of production of carbon(IV) oxide can be achieved using _______

A. 0.05 moI dm^-3 HCI and 5g powdered CaCO₃
B. 0.05 mol dm^-3 HCl and 5g lump CaCO₃
C. 0.10 moI dm^-3 HCl and 5g powdered CaCO₃ .
D. 0.025 mol dm^-3 HCI and 5g powdered CaCO₃.

50 cm³ of a gas was collected over water at 10^oC and 765 mm Hg. Calculate the volume of the gas at s.t.p. if the saturated vapour pressure of water at10^oC is 5mm Hg.

A. 49.19 cm³    B. 48.87 cm³    C. 48.55 cm³   D. 48.23 cm³

The pressure exerted by a gas is a function of the

A. total volume of the gas.
B. speed of the gaseous molecules.
C. mass of each gaseous molecule.
D. frequency of collision between gaseous molecules.

The electronic configuration of Mg²⁺ is ______

A. 1s² 2s² 2p⁶ 3s² 3p²   
B. 1s² 2s² 2p⁶ 3s²   
C. 1s² 2s² 2p⁶   
D. 1s² 2s² 2p⁴

A sample of a salt was heated on a Bunsen flame. If the colour of the flame turned bluish-green, the metal present is likely to be ______

(a) potassium    (b) copper    (c) sodium    (d) iron

The isomers of C₃H₈O are _______

A. 1 - propanol and 2- propanol
B. 1 - propanol and 1 - propanal
C. 2 - propanol and 2- propanone
D. 2- propanol and 1 - propanal.

An increase in entropy can best be illustrated by _______

A. mixing of gases     B. freezing of water    C. the condensation of vapour    D. solidifying candle wax

Methanoic acid mixes with water in all proportions and has about the same boiling point as water. Which of the following methods, would you adopt to obtain pure water from a mixture of sand, water and methanoic acid?  

A. Fractional distillation
B. Filtration followed by distillation
C. Neutralization with sodium hydroxide followed by distillation
D. Neutralization with sodium hydroxide followed by filtration