2023 Neco Chemistry Questions And Answer
1a.
(i) List three uses of sulphur.
(ii) Mention two physical properties of hydrogen sulphide.
(iii) State one difference between soaps and detergents.
(iv) Give one use of detergents.
b.(i)What is the number of neutrons in the following element:
(ii)Consider the reaction:
C.What is the mass of oxygen needed to burn 9.2 g of sodium?
(Na=23,0=16)
(iii) Calculate the number of moles of calcium chloride that can be obtained from 50g of limestone in the presence of excess hydrogen chloride.
[Ca=40,C=12,O=16,H=1,Cl=35.5]
(i) Mention two types of colloidal solutions.
(ii) State the law of definite proportions.
Calculate the relative molecular mass of the following:
I.Sodium trioxonitrate(V)
II. Copper (II) tetraoxosulphate (VI) pentahydrat
2a.
(i) Calculate the mass of silver deposited when a current of 4.6 A is passed through a solution of a silver salt for 90 minutes. [Ag=108,1 Faraday=96,500 C]
(ii) Give two factors that affect the discharge of ions during electrolysis.
(iii)Ideatify the oxidizing and reducing agents in the reaction below
Write the half cell equation in 2a(iii)
Draw and label the apparatus that can be used for the separation of two immiscible iquids
(ii) Mention three properties of gases.
(ii) State Faraday's second law of electrolysis
(iv) Name two amorphous forms of carbou.
(V) Arrange the following metals in order of decreasing chemical Reactivity;Mg,Al,Ca,Na.
3. Classify the following into primary,secondary and tertiary alkanols.
1 Butan-2-ol
2-methylpropanol
2-methylpropan-2-ol
(ii) State two methods by which ethanol can be prepared commercially
(i) If hydrogen diffuses 6 times as fast as a ges Z at the same temperature and pressure,calculate the relative moleclr mass of Z.[Relative molecular mass of hydrogen=2]
(i) Write the electronic configuration of oxygen,using s.p.df notation.
(ii) List three physical properties of oxygen.
(iii) Give two rules of naming alkenes.
(iv) Write an equation to show oxidation reaction of ethene.
4. Define an endothermic reaction.
(ii) Write the equation for the laboratory preparation of hydrogen by the action of dilute tetraoxosulphate(VI)acid on Zine.
(iii) State the type of reaction that is involved in c(li)
(iv) State three uses of hydrogen.
5.Caleulate the aumber of hydgen los prby
Mendion t ypes of heneal ombinations
(y) Date the conatitent and oe of the following sly sooner.
6.
Mention one difference between an alipatiad aromatie bydmcarbon
(y) An o10.8
7.Mention tree ctors at aie the rae of a chorical
State te law of conserVation of enery
Give two examples of chemical change
Compounds A and B reaer to form activaiedt complex AB producing compounts Cand D. Given that the emhaipy change is positive, draw the enargy profile diagram.
8.
Give twe characteristics of homologous series.
Write the twe geometric isomers of the molecule BrCH2CH=CHCH2 CH=CHCH2Br.
(ii) Name three types of iron.
(1) Calculate the mass of CuSO,that is required to prepare 500 cm3 solution of 0.25 moldm CuSO4
[Cu=64,8=32,0=16]
(ii) List twe sources of hydrocarbons.
(iii) Mention two advantages of catalytic cracking over thermal cracking.
Give one property of elements in the same period.
(V) What is the family name of group 2 elements?
I. Write an equation for the reaction of sulphur with hot concentrated tetraoxosuphate (VI) acid.
(ii) Write a balanced equation for the reaction between hydrogen sulphide and sulphur(IV)oxide
(iii) State the:
11Oxidizing agent in c(ii)
(2 marks)
Reducing agent in c(ii)
(iv) How many electrons are present in the following ions?
NECO 2023 CHEMISTRY OBJECTIVE QUESTIONS.
1.
The element X with electronic configuration 1s22s2 2p63s2 3p6 belongs to group
A. 0.
B. II.
C. III.
D. V.
E. VI.
2.
Consider the reaction represented by the equation: Zn(s)+2HCI(ag)→ZnCl2(mq)+H2(
Zn(s)+2HCI(
(g)
3.
What volume of hydrogen in dm3 would be produced at s.t.p. when 2.60 g of zinc reacts with excess hydrochloric acid?
[H=1,Cl=3=1,Cl=35.5,Zn=65,molar volume of a gas at s.t.p.t.p.=22.4dm3]
A.0.26
B.0.49
C.0.68
D.0.90
E.0.95
4.
Which of the following is not a monobasic acid?
A. Ethanoic acid
B. Hydrochloric acid
C. Hydrofluoric acid
D. Tetraoxosulphate(VI) acid
E. Trioxo nitrate(V) acid
5.
A sodium atom and a sodium ion have the same
A. chemical properties.
B. electric charges.
C. electronic structures.
D. number of electrons.
E. number of neutrons.
6.
In the endothermic reaction above, more product formation will be favoured by a/an
A. constant volume.
B. decrease in pressure.
C. decrease in volume.
D. increase in pressure.
E. increase in surface area.
7.
The separation technique that can be used to show that chlorophyll pigment is a mixture of different coloured chemical compounds is
A. chromatography.
B. crystallization.
C. distillation.
D. filtration.
E. sublimation.
9.
The weakest attractive force that exists between two molecules is
A. co-ordinate covalent.
B. covalent.
C. ionic.
D. metallic.
E. van der waals.
10.
Which of the following is a raw material for making glass?
A. Caustic potash
B. Hydrochloric acid
C. Limestone
D. Slaked lime
E. Sodium chloride
11.
The somal that sioplacer bydesges
Rusling of the metl pan of a tna om waler way can bee preventesl by andlic pnulection
cattrodis imutection.
B.regullar palinting of theTin pllating.
The ar poliutat that resuhis frum inoraane of uetare mumbber of petru is
C. Tetraethyd leat.
Which of the flving amino is
Irun mamy isxuneral can be butanet
12.
The reverse reaction of the equation below is?
C2H,OH+CH,COOH
C3H,OH+CH,COOHCH,COOC2H1+H2O
A. ester I fixation.
B. fermentation.
C. hydration.
D. hydrolysis.
E. saponification.
13.
Petrol can be obtained from crude oil by
A. catalysis.
B. cracking.
C. crystallization.
D. dehydrogenation.
E. distillation.
14.
Which of the following is not a fraction of petroleum?
A. Bitumen
B. Coal
C. Diesel
D. Kerosene
E. Petrol.
15.
When solutes are completely dissolved in a solvent,the product is called?
A. aerosol.
B. colloidal solution.
C. dispersion medium.
D. suspension.
E. true solution.
16.
The following oxides react with both acids and bases to form a salt excep
A. aluminium oxide.
B. carbon(IV) oxide.
C. lead(II)oxide.
D. tin (IV) oxide.
E. zinc oxide.
17.
When ammonia and hydrogen ion bond together to form ammonium ion,the bond formed is
A. covalent.
B. dative.
C. electrovalent.
D. hydrogen.
E. metallic.
18.
What volume in dm3 of oxygen at s.t.p.is required to convert 60 g of carbon completely into carbon(IV) oxide?
[C=12,O=16,molar volume 22.4dm]
A. 36.0
B. 44.8
C. 56.0
D. 112.0
E. 224.0.
19.
The pH value that indicates a basic solution is?
A. 1.
B. 2.
C. 3.
D. 7.
E. 9.
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