NECO GCE Chemistry Questions and Answers for Chemistry Students

NECO GCE Chemistry Questions are really important for students getting ready for their NECO GCE exams.

These questions cover lots of different areas in Chemistry, like the study of chemicals from living and non-living things, how substances change and react, and how to analyze chemical substances.

They’re mainly used to see if students understand the basic ideas of chemistry if they can work out problems involving numbers, and if they know how chemistry is used in everyday life.

Here are some examples of past Chemistry questions and their answers.

NECO GCE Chemistry Questions

(1ai) Which indicator would you choose for the titration of a strong acid against a strong base, and why?

(ii) What color does methyl orange turn in a basic solution?

(iii) Which strong acid is used in the titration process described?

(iv) Write the balanced chemical equation for the reaction between hydrochloric acid and sodium carbonate.

(bi) Calculate the concentration in moles per cubic decimeter (mol/dm³) of hydrochloric acid (HCl) if its concentration is given as 7.30 g/dm³. Assume the molar mass of HCl is 36.5 g/mol.

(ii) Given the volumes and the molar ratio of the reactants, calculate the concentration of solution B in moles per cubic decimeter (mol/dm³).

(iii) If solution B’s concentration is 0.2096 mol/dm³, calculate its molar mass given that its concentration in g/dm³ is 10.6.

(2ai) Based on your experiment, what can be inferred about a sample that dissolves in water?

(ii) Describe the observation and inference when a certain gas is evolved upon adding a reactant to sample X, which also turns red moist litmus paper blue.

(iii) What inference can you make if a gas evolves that forms a white fume with NaOH solution?

(iv) Based on the reactions observed, what can be inferred about the nature of the solution after all tests?

(3a) List two reagents that could be used to test for the presence of chloride ions in a solution.

(3b) Name the laboratory equipment or materials used in titration, specifically for delivering and measuring liquids, conducting the titration, and determining the endpoint.

Answers for NECO GCE Chemistry Practical Questions

Answer 1

(1ai) Methyl Orange

Reason:- Titration of strong acid against the base

1aii)Yellow

1aiii) Hydrochloric acid

1aiv)2HCL(aq)+ x2Co3 -> 2 x CLaq + H20(aq) + CO2(g)

(1b) The molar mass of HcL = 1+35.5
=36.5gmol^-1
Con of A is moldm^-3 =
Con of A of gdm^3/molar mass in gdm^3
=7.30gdm^-3/36.5gmol^-1
=0.200moldm^-3

1bii) using CAVA/CBVB = a/b
CA = 0.200mol/dm^3
VA = 26.20cm^3
Cb =?
VB = 25.0cm^3
a = 2mols
b = 1mol
0.200mol/dm^3 x 26.2cm^3/Cb x 25.0cm^3
= 2mols/1mol

Cb = 0.200×26.20×1/25.0×1

= 5.24/25.0mol/dm^3

Cb = 0.2096mol/dm^3

1biii)

Conc. of B in gdm-3/Conc of B in mol/dm-3
=10.6gdm-3/0.148 gdm-3
=101.15g
=101gmol-1

Answer 2

(2ai) INFERENCE:
Sample X is a soluble salt

(2aii) OBSERVATION:

Gas has evolved. The gas turns red moist litmus blue.

It forms a white fume when you add NaOH solution.

INFERENCE:

Alkaline gas

2aiii) INFERENCE:

CO3 gas is CO3^2-

(2aiv) INFERENCE:

The solution is alkaline

(3a) (i)NH4CL and AgNo3

(ii) ZnCo3

(iii) Fes

(iv) AgNo3

(v) NH4Cl

Answer 3

(3a) Two reagents commonly used to test for the presence of chloride ions in a solution are silver nitrate (AgNO3) and nitric acid (HNO3).

The reaction involves the formation of a white precipitate of silver chloride (AgCl) when chloride ions are present:

Ag++Cl−→AgCl

Silver nitrate (AgNO3) commonly detects chloride ions by forming a white precipitate of silver chloride when added to a chloride-ion-containing solution.

In chloride ion testing, it’s common to add nitric acid (HNO3) to the solution before introducing silver nitrate. This step helps avoid the precipitation of other silver salts.

(3b) (i) Burnette

(ii) Resort Hand

(iii) Solution/Acid

(iii) Conical Flask

(iv) White tile

The National Examinations Council (NECO) General Certificate Examination (GCE) is a very important test in Nigeria. 

It’s for students who want to get better grades than they did in their exams in May/June or just want to improve their school records.

Getting to know the kinds of questions that were asked before can help you do better and feel more confident when you take the actual test.