Year 10 Science · Unit 2 · Lesson 6
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Learning Goals
Because… chain
Fill in the missing effects to trace how the Haber process connects to feeding billions of people.
Overall significance of the Haber process:
Real-world context
When hydrogen peroxide (H₂O₂) solution is poured onto a fresh cut or wound, it fizzes vigorously. This occurs because an enzyme called catalase, present in living cells and blood, acts as a biological catalyst and causes hydrogen peroxide to decompose rapidly. In intact, unbroken skin, catalase is sealed inside cells; on raw flesh or open wounds, catalase is exposed directly to the H₂O₂. This is why first-aid kits in Australian schools and workplaces often include 3% H₂O₂ solution.
(a) Write the word equation for the decomposition of hydrogen peroxide. Classify the reaction type (synthesis or decomposition) and identify the two products.
(b) The fizzing of H₂O₂ on a wound is evidence of a chemical reaction. Identify which sign of a chemical reaction is visible, and explain why the production of O₂ gas, rather than some other sign, confirms that decomposition specifically has occurred.
(c) The same H₂O₂ solution fizzes much more vigorously on raw flesh than on intact skin. Using your knowledge of catalase and catalysts, explain why this difference in fizzing rate occurs.
1. Cement production involves heating limestone (CaCO₃) to produce lime (CaO) and carbon dioxide gas. Identify the reaction type, classify it as endothermic or exothermic, and explain why large amounts of energy are needed for this reaction in an industrial kiln.
Wrap Up
In one sentence, what was the main idea of this lesson?