1. Two Methods of Domestic Water Treatment:
i. Filtration: This process involves passing water through a filter medium to remove impurities and contaminants.
ii. Chlorination: This method involves adding chlorine or chlorine compounds to water to kill harmful microorganisms and disinfect the water.
6. Experiment Preparation and Assembly:
i. What can you prepare from the materials above? You can prepare oxygen gas by using manganese (IV) oxide as a catalyst to decompose hydrogen peroxide when water is present.
ii. Draw a diagram to show how you can assemble your experiment: (Please envision the following setup, as I cannot draw directly.)
- A flat-bottomed flask containing hydrogen peroxide and manganese (IV) oxide.
- A delivery tube connected to the flask leading to a gas jar placed upside down in a trough of water.
- The dropping funnel could be used to introduce the reactants into the flask if needed.
Gas Jar
|
|
+-------|-------+
| | |
--- | |
| | | |
| | | |
Flask Through Water Trough
| |
| |
+----------+
iii. Write any two uses of what you would obtain from the above experiment:
- The oxygen gas produced can be used for respiration in aquariums and to support combustion in various applications.
- It can also be utilized in medical applications, such as providing supplemental oxygen to patients.
iv. Write a word chemical equation for the reaction in the arranged experiment: Hydrogen Peroxide → Water + Oxygen (Gas)
7. Experiment with Iron Pieces:
i. What was the aim of the experiment? The aim of the experiment was to investigate the effect of painting on the corrosion of iron when exposed to a moist environment.
ii. Which of the two pieces of iron would be heavier? The piece of iron Y (unpainted) would likely be heavier after the experiment.
iii. Give reason to support your answer: Iron piece Y (unpainted) would corrode due to moisture exposure, resulting in the formation of rust (iron oxide), which would add mass. In contrast, piece X (painted) would experience minimal corrosion and remain largely intact, resulting in less mass gain.
iv. Give and define the suitable chemical name describing what happened on the piece of iron named in 7 (ii) above: The suitable chemical name is oxidation. Oxidation is the process where iron reacts with oxygen and moisture to form iron oxide (rust), leading to deterioration of the metal.
8. (a) Diagram for Fractional Distillation:
(Please envision the following setup, as I cannot draw directly.)
- A distillation flask with a mixture of petrol, diesel, and kerosene heated to a temperature where components vaporize.
- A fractional distillation column with packing material to facilitate separation.
- An exit tube to collect vapors that condense and flow into separate containers for each fraction.
Condenser
|
+--------|---------+
| | |
Flask | Collection
(Heat) | Flasks
| | for petrol
| -----> Condensed Liquid
|
Fractional
Distillation
Column
(b) Describe using three points to show how the separation of mixtures is important: i. Purity of Products: Separating mixtures ensures that each component is obtained in a pure form for use in various applications, such as fuel, solvents, or chemical reactants.
ii. Efficiency in Industrial Processes: In industries, separation techniques like fractional distillation enable the efficient extraction of desired products from raw materials, thereby minimizing waste and maximizing yield.
iii. Environmental Protection: Separation processes can help in removing impurities and pollutants from materials, contributing to environmental sustainability and safety in various sectors.