NECO GCE Chemistry questions encompass various aspects of the subject, exploring the study of chemicals from both living and non-living sources, chemical reactions, and applications in everyday life. Here's a breakdown of typical questions along with answers:
Questions for NECO GCE Chemistry Practical 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.
(3a ii-v) Identify the compounds or reagents based on their reaction or usage in a practical scenario.
(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
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
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
(3b) (i) Burnette
(ii) Resort Hand
(iii) Solution/Acid
(iii) Conical Flask
(iv) White tile
Conclusion
Preparation for the NECO GCE Chemistry exam is crucial for students aiming to excel academically. By familiarizing themselves with past questions and understanding the underlying principles, students can approach the exam with confidence and achieve their desired outcomes.
Related
- Kano State Polytechnic (KANOPOLY) Announces Revised Dates for 2023/2024 Semester Exams
- 11 Tips to Ace WAEC in Just One Sitting
- Mastering Exam Preparation: Essential Steps for Success
- Official 2024 WASSCE Timetable Released by WAEC: Plan Your Exam Success
- NECO Computer Studies Questions for Computer Science Students