Chemistry Exam Questions - Grade 12 ESSLCE 2023

Chemistry - Grade 12 -2023 G.C

Grade 12 students can now access their exam results by visiting the Educational Assessment and Examination Services (EAES) website.

60. Given the following:
bond energies (kJ/mol)
H-H 936
N-N 193
N=N 409
N≡N 942
and the enthalpy for the reaction $\frac{1}{2} N_{2} (g) + \frac{3}{2} H_{2} (g)$ → ${NH}_{3} (g); ΔH = -45 kJ/mol$ What is the bond energy for NH₃?

	bond energies (kJ/mol)
H-H	936
N-N	193
N=N	409
N≡N	942

1080
960
1170
1125

61. Which of the following would occur during the formation of ions?

Valence electrons are transferred from one atom to another.
The electronic configuration of an atom forming the ion remains unaffected.
Valence electrons are shared between atoms.
Inner most shell electrons are involved.

62. In order to illustrate the structure and properties of a solid, a student put hundred marble balls in to a box that representing metal cations and the empty space between and around the marble representing the electron sea. Which one of the following bonding is represented by this model?

Dative bonding
Metallic bonding
Ionic bonding
Covalent bonding

63. Which one of the following explains dipole-dipole force?

An electrostatic attraction between metal ions and valence electrons.
An attractive force resulting from temporary dipoles induced in molecules.
The intermolecular attraction between oppositely charged poles of nearby polar molecules.
A type of intermolecular force that exists between non- polar molecules.

64. Which one of the following reactions creates energy in our bodies during respiration?

N2H4CO(g)+H2O(g) → $2 {NH}_{3} (l) + {CO}_{2} (g)$ " > $N_{2} H_{4} CO (g) + H_{2} O_{} (g)$ → $2 {NH}_{3} (l) + {CO}_{2} (g)$
C6H12O6(s) → $2 C_{2} H_{5} OH (l) + 2 {CO}_{2} (g)$ " > $C_{6} H_{12} O_{6} (s)$ → $2 C_{2} H_{5} OH (l) + 2 {CO}_{2} (g)$
6CO2(g)+6H2O(l) → $C_{6} H_{12} O_{6} (s) + 6 O_{2} (g) " > 6 {CO}_{2} (g) + 6 H_{2} O (l) → C_{6} H_{12} O_{6} (s) + 6 O_{2} (g)$
C6H12O6(s)+6O2(g) → $6 {CO}_{2} (g) + 6 H_{2} O (l)$ " > $C_{6} H_{12} O_{6} (s) + 6 O_{2} (g)$ → $6 {CO}_{2} (g) + 6 H_{2} O (l)$

We have provided these questions from previous years grade 12 Ethiopian Secondary School Leaving Certificate Examination (ESSLCE) exams with the sole purpose of assisting students in their studies and preparations for upcoming exams. Please be aware that these questions are not indicative of future exam content. Good luck with your studies!

60. Given the following:bond energies (kJ/mol)H-H936N-N193N=N409N≡N942and the enthalpy for the reaction 12N2(g)+32H2(g) → NH3(g);ΔH = -45 kJ/mol What is the bond energy for NH3?

61. Which of the following would occur during the formation of ions?

62. In order to illustrate the structure and properties of a solid, a student put hundred marble balls in to a box that representing metal cations and the empty space between and around the marble representing the electron sea. Which one of the following bonding is represented by this model?

63. Which one of the following explains dipole-dipole force?

64. Which one of the following reactions creates energy in our bodies during respiration?

60. Given the following:
bond energies (kJ/mol)
H-H 936
N-N 193
N=N 409
N≡N 942
and the enthalpy for the reaction $\frac{1}{2} N_{2} (g) + \frac{3}{2} H_{2} (g)$ → ${NH}_{3} (g); ΔH = -45 kJ/mol$ What is the bond energy for NH₃?