Solve this other chemistry paper 111 Ijmb question for me

here are the solutions for the chemistry practical paper:

Q1 (a): Prepare $0.10 mole dm^{-3}$ of $\text{HNO}_3$ as solution D.

Step 1: Determine the volume of concentrated $\text{HNO}_3$ needed. To prepare $1 dm^3$ ($1000 cm^3$) of $0.10 mol dm^{-3}$ $\text{HNO}_3$ solution, we first need to find the molarity of concentrated $\text{HNO}_3$. Assuming concentrated $\text{HNO}_3$ is $68\%$ w/w with a density of $1.42 g/cm^3$ and molar mass of $\text{HNO}_3$ is $63.01 \text{ g/mol}$: $Molarity of conc. HNO_3 = \frac{68 \times 1.42 g/cm^3 \times 1000 cm^3/dm^3}{63.01 g/mol \times 100} = 15.33 mol/dm^3$ Using the dilution formula $C_1V_1 = C_2V_2$: $15.33 mol/dm^3 \times V_1 = 0.10 mol/dm^3 \times 1 dm^3$ $V_1 = \frac{0.10 mol/dm^3 \times 1 dm^3}{15.33 mol/dm^3} = 0.00652 dm^3 = 6.52 cm^3$

Step 2: Outline the preparation procedure. • Carefully measure out $\mathbf{6.52 cm^3}$ of concentrated $\text{HNO}_3$ using a measuring cylinder or pipette. • Pour about $500 cm^3$ of distilled water into a $1 dm^3$ volumetric flask. • Slowly add the measured concentrated $\text{HNO}_3$ to the water in the volumetric flask, swirling gently. (Always add acid to water). • Add more distilled water until the solution is just below the calibration mark. • Stopper the flask and invert several times to mix. • Add distilled water dropwise until the bottom of the meniscus aligns with the $1 dm^3$ calibration mark. • Stopper and invert the flask several times to ensure thorough mixing. • Label the solution as Solution D ($0.10 mol dm^{-3}$ $\text{HNO}_3$). This stock solution can then be dispensed in $200 cm^3$ portions to each student.

Q1 (b): Prepare $0.04 mole dm^{-3}$ of $\text{Na}_2CO_3 \cdot 10H_2\text{O}$ as solution E.

Step 1: Calculate the mass of $\text{Na}_2CO_3 \cdot 10H_2\text{O}$ needed. To prepare $1 dm^3$ ($1000 cm^3$) of $0.04 mol dm^{-3}$ $\text{Na}_2CO_3 \cdot 10H_2\text{O}$ solution. Molar mass of $\text{Na}_2CO_3 \cdot 10H_2\text{O}$: $(2 \times 22.99) + 12.01 + (3 \times 16.00) + (10 \times (2 \times 1.008 + 16.00)) = 286.15 \text{ g/mol}$. Mass needed = Molarity $\times$ Volume $\times$ Molar mass $Mass = 0.04 mol/dm^3 \times 1 dm^3 \times 286.15 g/mol = 11.446 g$

Step 2: Outline the preparation procedure. • Weigh out $\mathbf{11.45 g}$ of $\text{Na}_2CO_3 \cdot 10H_2\text{O}$ accurately using a digital balance. • Transfer the weighed solid into a beaker and dissolve it in about $200 cm^3$ of distilled water. Stir to ensure complete dissolution. • Carefully transfer the solution into a $1 dm^3$ volumetric flask using a funnel. • Rinse the beaker and funnel with small portions of distilled water and add the rinsings to the volumetric flask to ensure all solute is transferred. • Add distilled water until the solution is just below the calibration mark. • Stopper the flask and invert several times to mix. • Add distilled water dropwise until the bottom of the meniscus aligns with the $1 dm^3$ calibration mark. • Stopper and invert the flask several times to ensure thorough mixing. • Label the solution as Solution E ($0.04 mol dm^{-3}$ $\text{Na}_2CO_3 \cdot 10H_2\text{O}$). This stock solution can then be dispensed in $125 cm^3$ portions to each student.

Q1 (c): Prepare $0.08 mole dm^{-3}$ of KOH as solution F.

Step 1: Calculate the mass of KOH needed. To prepare $1 dm^3$ ($1000 cm^3$) of $0.08 mol dm^{-3}$ KOH solution. Molar mass of KOH: $39.10 + 16.00 + 1.008 = 56.108 \text{ g/mol}$. Mass needed = Molarity $\times$ Volume $\times$ Molar mass $Mass = 0.08 mol/dm^3 \times 1 dm^3 \times 56.108 g/mol = 4.48864 g \approx 4.49 g$

Step 2: Outline the preparation procedure. • Weigh out $\mathbf{4.49 g}$ of KOH pellets quickly, as it is hygroscopic, using a digital balance. • Transfer the weighed solid into a beaker and dissolve it in about $200 cm^3$ of distilled water. Stir to ensure complete dissolution. (Note: Dissolution of KOH is exothermic). • Allow the solution to cool to room temperature. • Carefully transfer the cooled solution into a $1 dm^3$ volumetric flask using a funnel. • Rinse the beaker and funnel with small portions of distilled water and add the rinsings to the volumetric flask. • Add distilled water until the solution is just below the calibration mark. • Stopper the flask and invert several times to mix. • Add distilled water dropwise until the bottom of the meniscus aligns with the $1 dm^3$ calibration mark. • Stopper and invert the flask several times to ensure thorough mixing. • Label the solution as Solution F ($0.08 mol dm^{-3}$ KOH). This stock solution can then be dispensed in $125 cm^3$ portions to each student.

Q1 (d): Prepare methyl orange and phenolphthalein indicators.

Step 1: Prepare Methyl Orange indicator. • Dissolve $\mathbf{0.1 g}$ of methyl orange powder in $100 cm^3$ of distilled water. Stir until completely dissolved.

Step 2: Prepare Phenolphthalein indicator. • Dissolve $\mathbf{1 g}$ of phenolphthalein powder in $100 cm^3$ of ethanol (or industrial methylated spirit). Stir until completely dissolved.

Q2: Provide samples and reagents.

• Provide $\mathbf{2 g}$ of Tin(II) Chloride labeled as SAMPLE B1. • Provide $\mathbf{2 g}$ of 2-Hydrobenzoic Acid (Salicylic Acid) labeled as SAMPLE B2. • Ensure that all necessary test reagents for inorganic and organic qualitative analysis are provided in the laboratory benches as instructed.

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