2010 Chemistry Neco Objective Questions

Which of the following methods is used in separating a mixture of palm wine and water?

A sample of orange juice is suspected to have been contaminated with a yellow dye. Which of the following methods can be used to detect the dye?

A salt which loses mass when exposed to air is

A particle that contains 17 protons, 18 neutrons and 18 electrons is

When pollen grains are suspended in water and viewed under a microscope, they appear to be in a state of constant but erratic motion. This is due to

The atomic mass of an atom is mostly due to the mass of

The atomic mass number of an element is 10, then the outermost shell will have ______ electrons

Water has a rather high boiling point despite its low molecular mass because the presence of bonding.

The type of bond between two atoms of an element with atomic number 7 each is

The chemically unreactive group of elements is called the

Which of the following indicates the correct increasing order of oxidizing power of the halogens

Br – I – Cl – F

Cl – F – I – Br

F – Cl – Br – I

I – Br – Cl – F

I – Cl – Br – F

Elements in the same group in the periodic table have the same

The following are periodic properties EXCEPT

If the rate of diffusion of oxygen gas is I, what will be the rate of diffusion of methane whose relative molar mass is 16?

According to the kinetic molecular theory, molecules are in random motion. This motion is greatest when a substance is changing from

The complex salt formed when aluminum dissolves in sodium hydroxide solution is

X acid is colorless when pure but often yellowish due to dissolved nitrogen(iv)oxide by slight decomposition of the acid. X is

A salt derived from a strong base and a weak acid will undergo hydrolysis and give a solution which will be

_________ of an acid is the number of replaceable Hydrogen ions in one molecule of the acid

Which of the following salts is most conveniently prepared by neutralization method?

Na₂CO_(aq) +  2HCl_(aq) + 2NACl_(aq) + H₂O + CO_{2 (g)} Using the equation above, what volume of carbon (IV) oxide in dm³ measured at s.t.p is liberated when 36g of sodium trioxocarbonate (IV) is dissolved in hydrochloric acid (1 mole of gas occupies 22.4dm³ at stp) [Na =23, C=12, O=16]

If 14.8g of a salt dissolved in 25cm³ of distilled water with a concentration of 0.80 moldm^-3. The molar mass of the salt in gmol^-1 is

Which of the following is a frozen planet

The mass of carbon in grams needed to reduce 15.9of copper (II) oxide is [C=12 Cu=63.5 O=16]

In the reaction

2Pb(NO₃)_2(s)  2 PbO _(s) + 4NO_{2 (g)}

Which of the following is true of an endothermic reaction?

Which of the following statements is correct? Rate of chemical reaction can altered by the

Which of the following compounds will form a solution when exposed to air?

In the electrolysis of brine, the anode is

Which of the following reactions takes place in the cathode compartment during the electrolysis of copper (II) chloride solution?

When the concentration of an electrolyte decreases, the conductivity

N₂O₄(g)    2NO₂(g). In the endothermic reaction above, more product will be formed a/an

Calculate s in JK^-1 mol ^-1 for the conversion of one mole of liquid water to vapour at 100C given that the heat of vaporization of water        = 2260.87Jg^-1

A measure of the degree of disorderliness in a chemical system is known as the

2KBr + Cl₂        2KCl + Br₂  In the reaction above, the role of chlorine is that of a/an

Alkanol + Alkanoic acid Ester + Water .   The reverse reaction of the equation is known as

What is the product of the reaction between ethanol and excess acidized KMnO₄ solution?

Which of the following compounds is a member5 of the series with the general molecular formula   C_nH_2n-2 ?

Which of theses compounds will react with NaOH to form a salt?

Alkanoates are produced from alkanols by

The compound with the structure above is an

What is the IUPAC name of the compound with the following structure?

Which of the following is an allotropic form of oxygen?

When steam is passed over white hot coke, the products are:

Which of the following is an allotropic form of oxygen?

Which of the following equations represents the reaction of Chlorine with hot concentrated sodium hydroxide solution?

In the laboratory preparation of Chlorine, the drying agent used is

Halogens are strong

Chlorine is NOT used in

Which of the following gases is colourless, odourless and soluble in KOH solution?

A mixture of two immiscible liquids can be separated by

Which of these is NOT a property of metals?

The best way to distinguish between Na₂CO₃ and  NaHCO₃ is by

The green colour solution of an Iron (II) salt changes to a brown colour solution of Iron (III) salt by a process known as

Which of the following is a frozen planet

A plastic which CANNOT be softened by heat is described as

What type of bond exists in sodium chloride?

A plastic which CANNOT be softened by heat is described as

Which of the following statements is correct? Rate of chemical reaction can altered by the

The following are divisions of chemical industries EXCEPT

Which of the following equations represents a Beta decay?

State TWO differences between chemical properties of metals and non-metals

(a).i. State TWO differences between chemical properties of metals and non-metals

1. List TWO methods of extracting metals from their ores

(b) i. State Avogadro’s law

i.  Which state of matter contains that are

i. Readily compressed

ii. Held firmly together by some forces of cohesion?

iii. Involved in rapid random motion?

(c) i. Which of the elements represented as A to E in the table above is

i. a transition metal?

ii. an alkaline earth metal?

III. least reactive?

iv. the most electronegative

ii. Name the type of bond that exists in a compound formed when element D reacts with oxygen

(d) Write equations for the reactions at each electrode when a dilute solution of sodium chloride is electrolysed using carbon electrodes

a(i) Methane reacts with chlorine under a certain condition to produce tetrachloromethane.

i. State the condition for the reaction

ii. Name the reaction

iii. Mention TWO uses of methane

iv.  Name ONE major natural source of ethanoic acid

bi.  Mention ONE similarity between the reaction of ethanol with sodium and that of sodium with water

ii. Write the two structures of TWO isomers of C₃H₈O

iii. Differentiate between a fine chemical and a heavy chemical and cite ONE example of each.

c. Explain the following observations:

i. Crystals of washing soda become powdery on exposure to air for a long time

ii. Give the IUPAC name of the following salts: CoCl₂ and Mg(NO₃)₂

iii. State ONE physical method and ONE chemical method in each case by which the following can be removed from water:

(a).  Permanent hardness

(b).  A suspension of CaCO₃

(a) i. Draw a labeled diagram for the laboratory preparation of a dry sample of chlorine gas.
ii. Give TWO differences between conductors and electrolytes

(b) Write equations to represent the reaction of chlorine gas with:

i. iron(ii) chloride solution
ii. hot concentrated sodium hydroxide solution
iii. potassium iodide solution

(c) state what is observed on:

I. bubbling hydrogen chloride gas into an aqueous solution of lead trioxonitrate (v)

II. heating the mixture from c(i) above to boiling and then allow it cool.

(d) Define oxidation in terms of electron transfer.

Identify the specie that is reduced in the equation above.

(a) Define the term-hydrocarbons

i. A hydrocarbon consist of 92.3% carbon. If its vapour density is 39, determine its molecular formula. (H=1, C=12)

(b) Outline a suitable procedure for obtaining ethanol from cassava tubers

i. List TWO laboratory reagents needed to oxidize ethanol to ethanoic acid.

c. What name is given to each of the following processes:

i. conversion of alkanols to alkanoates

ii. breaking down of proteins to amino acids

iii. conversion of oils to fats

iv. alkaline hydrolysis of fats and oils

(c) Potassium trioxochlorate (v) undergoes thermal decomposition according to the following equation

d. What substance could be used in the laboratory to:

a. Increase the rate of the reaction

b. Absorb the oxygen produced

(a) i. Define heat of combustion
ii. Name the container used for determining the heat of a reaction

(b) i. The heat of combustion of carbon in excess air is 3935 kJ

ii. Sketch an energy profile diagram for the reaction
iii. Explain why the value of the heat of neutralization of strong acids by strong bases is constant

(c) Give the reasons for the following:

i. rusting of iron is regarded as slow combustion

ii. an aqueous solution of silver trioxonitrate (v) gives a white precipitate with KCl but not with KClO₃

iii. iron is better protected from corrosion by plating it with zinc than with tin

(d) When ethane 1,2 dioc acid is heated with conc. H₂SO₄ acid, a reaction represented by the following equation occurs

i. Name the type of process involved in the reaction

ii. What is the basicity of ethane-1,2-dioic acid?

iii. List THREE differences in the chemical properties of the two oxides produced during the reaction.