AQA AS Specimen Paper 2 Q5

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12 CCl4 is an effective fire extinguisher but it is no longer used because of its toxicity and its role in the depletion of the ozone layer. In the upper atmosphere, a bond in CCl4 breaks and reactive species are formed. Identify the condition that causes a bond in CCl4 to break in the upper atmosphere. Deduce an equation for the formation of the reactive species. [2 marks] Condition Equation One of the reactive species formed from CCl4 acts as a catalyst in the decomposition of ozone. Write two equations to show how this species acts as a catalyst. [2 marks] Equation 1 Equation 2 A small amount of the freon CF3Cl with a mass of 1.78104 kg escaped from a refrigerator, into a room of volume 100 m3. Assuming that the freon is evenly distributed throughout the air in the room, calculate the number of freon molecules in a volume of 500 cm3. Give your answer to the appropriate number of significant figures. [3 marks] The Avogadro constant = 6.021023 mol1. Number of molecules = Typesetter code . 1 0 5 . 2 0 5 . 3 0 5 Barcode<br /> 13 Turn over for the next question DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED Barcode Typesetter code Turn over <br />

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