2.4. Reacting masses and volumes (of solutions and gases)
A subsection of Chemistry, 9701, through 2. Atoms, molecules and stoichiometry
Listing 10 of 98 questions
Use of the Data Booklet is relevant to this question. A significant contribution to atmospheric carbon dioxide levels comes from the thermal decomposition of limestone, in the manufacture of cement and of lime for agricultural purposes. Cement works roast 1000 million tonnes of limestone per year and a further 200 million tonnes is roasted in kilns to make lime. What is the total annual mass output of carbon dioxide (in million tonnes) from these two processes?
9701_w11_qp_11
MCQ
2011
Paper 1, Variant 1
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Use of the Data Booklet is relevant to this question. A significant contribution to atmospheric carbon dioxide levels comes from the thermal decomposition of limestone, in the manufacture of cement and of lime for agricultural purposes. Cement works roast 1000 million tonnes of limestone per year and a further 200 million tonnes is roasted in kilns to make lime. What is the total annual mass output of carbon dioxide (in million tonnes) from these two processes?
9701_w11_qp_13
MCQ
2011
Paper 1, Variant 3
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Carbon dioxide, CO2, makes up about 0.040 % of the Earth’s atmosphere. It is produced by animal respiration and by the combustion of fossil fuels. In animal respiration, oxygen reacts with a carbohydrate such as glucose to give water, carbon dioxide and energy. The typical daily food requirement of a human can be considered to be the equivalent of 1.20 kg of glucose, C6H12O6. You should express all of your numerical answers in this question to three signifi cant fi gures. Construct a balanced equation for the complete oxidation of glucose. Use your equation to calculate the amount, in moles, of CO2 produced by one person in one day from 1.20 kg of glucose. On the day on which this question was written, the World population was estimated to be 6.82 × 109. Calculate the total mass of CO2 produced by this number of people in one day. Give your answer in tonnes. [1 tonne = 1.00 ×106 g] When fossil fuels are burned in order to give energy, carbon dioxide and water are also produced. The hydrocarbon octane, C8H18, can be used to represent the fuel burned in motor cars. A typical fuel-effi cient motor car uses about 4.00 dm3 of fuel to travel 100 km. Construct a balanced equation for the complete combustion of octane. The density of octane is 0.700 g cm–3. Calculate the amount, in moles, of octane present in 4.00 dm3 of octane. Calculate the mass of CO2 produced when the fuel-effi cient car is driven for a distance of 100 km. Calculate how many kilometres the same fuel-effi cient car would have to travel in order to produce as much CO2 as is produced by the respiration of 6.82 × 109 people during one day. Use your answer to . Carbon dioxide is one of a number of gases that are responsible for global warming. When fossil fuels such as octane are burned in a car engine, other atmospheric pollutants are also produced. Give the formula of one atmospheric pollutant that may be produced in a car engine, other than CO2, and state how this pollutant damages the environment. pollutant damage caused
9701_w12_qp_23
THEORY
2012
Paper 2, Variant 3
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Questions Discovered
98