Grade 9 Natural Sciences June 2025 Provincial Examination Study Notes

Examination Overview and Administrative Details

This document covers the Grade 9 Natural Sciences June 2025 examination for the Free State Province Department of Education. The examination was designed for a duration of 1 hour with a grand total of 50 marks. The paper consists of 8 pages, including a periodic table on the final page. The assessment is divided into two primary sections: Section A, which carries 10 marks, and Section B, which carries 40 marks.

Specific instructions provided to the students include the following requirements: all questions must be answered in the provided answer book; the numbering system must correspond exactly to the question paper; students are instructed to leave one open line between sub-questions (e.g., between QUESTION 2.1.1 and QUESTION 2.1.2); all handwriting must be neat and legible; a Periodic Table is provided as a reference on the final page of the paper.

Section A: Objective Questions and Matching

Section A consists of multiple-choice questions (Question 1.1) and a matching column task (Question 1.2), totaling 10 marks.

Question 1.1: Multiple Choice Questions. Students were required to select the correct answer from four options (A–D):

• 1.1.1: Identification of the element with atomic number 1. The options include Helium, Lithium, Hydrogen, and Oxygen. The correct answer is Hydrogen ($C$).
• 1.1.2: Identifying the name of the chemical compound $CaCO_3$. The correct name is Calcium carbonate ($A$).
• 1.1.3: Identifying reactants in the chemical reaction $N_2 + 3H_2 \rightarrow 2NH_3$. The reactants are $N_2$ and $H_2$ ($B$).
• 1.1.4: Matching chemical formulae for sulphur trioxide, nitrogen dioxide, and carbon monoxide. The correct set is Sulphur trioxide ($SO_3$), Nitrogen dioxide ($NO_2$), and Carbon monoxide ($CO$) ($B$).
• 1.1.5: Example of a non-metal oxide. Options include $MgO$, $CaO$, $Na_2O$, and $CO_2$. The correct answer is $CO_2$ ($D$).

Question 1.2: Matching Columns. Match Column A descriptions to Column B items:

• 1.2.1: A solution with a pH of less than 7 corresponds to an Acidic solution ($D$).
• 1.2.2: A reaction between an acid and a base is defined as Neutralisation ($E$).
• 1.2.3: An example of a slow irreversible chemical reaction is Rusting ($A$).
• 1.2.4: Typical products of a neutralisation reaction include Salt and water ($B$).
• 1.2.5: A substance used in agriculture to decrease acidity in soil is a Metal oxide ($C$).

Section B: Matter and Materials - The Periodic Table and Equations

Question 2 (13 marks) focuses on the Periodic Table and chemical structures. A diagram provided labels specific elements with letters (B, R, Q, L, G, W, A, Z) at various positions on the table.

2.1 Analysis based on the Provided Diagram:

• 2.1.1: The element with the smallest atomic number in the diagram is identified as Element B (Sodium/$Na$ according to its position).
• 2.1.2: The two metals with similar chemical properties (belonging to the same group) are identified as R and A (Calcium and Barium).
• 2.1.3: The two non-metals found in the same period are L and G (Phosphorus and Chlorine).

2.2 Particle Structure of Element G: The atom is represented as $_{17}^{35}Cl$.

• 2.2.1: The number of electrons in this neutral atom is $17$.
• 2.2.2: The number of neutrons in this atom is calculated as the mass number minus atomic number ($35 - 17 = 18$).
• 2.2.3: The compound formed when element G (Chlorine) reacts with element B (Sodium) is Sodium chloride.

2.3 Elements and Compounds:

• 2.3.1: $CO_2$ is classified as a compound because it consists of atoms from different elements (Carbon and Oxygen) chemically bonded together.
• 2.3.2: $O_2$ is classified as an element because it consists of two atoms of the same chemical element.

2.4 Chemical Models and Balancing:

• 2.4.1: Students are provided with spherical models for Hydrogen (small circles) and Chlorine (larger circles). They must translate a pictorial equation into a balanced chemical equation: $H_2 + Cl_2 \rightarrow 2HCl$.
• 2.4.2: This equation is balanced because the number of atoms of each element ($2$ Hydrogen atoms and $2$ Chlorine atoms) is identical on both the reactant (left) and product (right) sides of the equation.

2.5 Balancing Exercise: The unbalanced equation $H_2O_2 \rightarrow H_2O$ is provided. According to the specific marking guidelines for this test, the balanced version is given as $2H_2O_2 \rightarrow 2H_2O$. (Note: While standard chemistry would include oxygen gas as a product, the note follows the instructional requirement of the paper).

Section B: Chemical Reactions - Combustion and Oxides

Question 3 (14 marks) describes two demonstrations involving combustion.

• Demonstration A: Yellow sulphur powder is heated until it ignites with a bluish-purple flame, producing a suffocating smell.
• Demonstration B: A shiny strip of magnesium ribbon is heated and burns with a bright blinding white flame.

3.1 Common Reactant: The reactant required for combustion in both cases is Oxygen ($O_2$).

3.2 Analysis of Demonstration A (Sulphur):

• 3.2.1: The chemical symbol for sulphur is $S$.
• 3.2.2: Sulphur is classified as a non-metal.
• 3.2.3: The name of the product formed is sulphur dioxide.
• 3.2.4: The product, sulphur dioxide, exists in the gas phase.
• 3.2.5: Balanced equation: $S + O_2 \rightarrow SO_2$.

3.3 Analysis of Demonstration B (Magnesium):

• 3.3.1: Magnesium is classified as a metal.
• 3.3.2: The flame color is white (or blinding white).
• 3.3.3: Word equation: $Magnesium + Oxygen \rightarrow Magnesium \, oxide$.
• 3.3.4: Description of the product: It is a white solid (or powder).

Section B: Acids, Bases, and Neutralization

Question 4 (13 marks) involves the reaction between magnesium oxide and hydrochloric acid.

4.1 Universal Indicator in Magnesium Oxide ($MgO$): The color will be blue or purple. This is because magnesium is a metal, and metal oxides are basic in nature, resulting in a pH above 7.

4.2 Addition of Hydrochloric Acid ($HCl$):

• 4.2.1: The pH of the hydrochloric acid solution is below 7.
• 4.2.2: The color changes to green because as acid is added, the basic magnesium oxide solution becomes less basic (and more acidic) until it reaches the neutral point (pH 7), at which point universal indicator turns green.

4.3 General Equations: The general word equation for this reaction type is: $\text{metal oxide} + \text{acid} \rightarrow \text{salt} + \text{water}$.

4.4 Product Formation: The product of the reaction between $MgO$ and $HCl$ has a Mg:Cl ratio of 1:2. This product is Magnesium chloride, with the chemical formula $MgCl_2$.

4.5 Balanced Chemical Equation: The balanced equation for the reaction is: $MgO + 2HCl \rightarrow MgCl_2 + H_2O$.

Supplementary Resource: Grade 8 Natural Sciences Marking Guidelines

Pages 11 through 13 of the transcript provide marking guidelines for a Grade 8 Natural Sciences test, also dated June 2025. These are retained here for exhaustive detail.

Section A (Grade 8):

• 1.1 Multiple Choice: 1.1.1 (C), 1.1.2 (A), 1.1.3 (C), 1.1.4 (B), 1.1.5 (D).
• 1.2 Matching: 1.2.1 (D), 1.2.2 (A), 1.2.3 (E), 1.2.4 (H), 1.2.5 (B).

Section B (Grade 8):

• Question 2: Identification of Helium, Calcium, Magnesium, and Silicon. Discusses Boron ($B$) containing 5 protons in the nucleus and an equal number of electrons, making it neutral.
• Question 3: Formulae for Hydrogen gas ($H_2$), Water ($H_2O$), and Carbon dioxide ($CO_2$) are identified.
• Question 4: Discusses states of matter. Solids are identified as having particles that are closely packed in a regular arrangement with very small spaces between them. Covers change of state processes: Condensation, Melting (wax changes to liquid), and Solidification (liquid changes to solid).
• Question 5: Density and Expansion. Includes a calculation for a cube (2cm sides) with mass 6,88g. Volume = $2 \times 2 \times 2 = 8\,cm^3$. Density = $\frac{6,88}{8} = 0,86\,g/cm^3$. Discusses ball expansion when heated (particles move further apart and faster, though the number of particles remains the same).
• Question 6: Hydrogen Fuel Cells. Reactants include Oxygen and Hydrogen. The product is Water (vapour). It is considered clean energy as no harmful gases are released.