“Carbon and Its Compounds: Challenge Problems” is available to Standard subscribers.
The chapter gave you the rules. Here you use them together. How many structures can a formula have? Which compound has these percentages? How much carbon dioxide does a fuel make, and how much soap is lost? In this course you learn two strategies and then solve harder problems, in the style of an olympiad.
3Lessons9Problems2Python Labs1Question Set1Mock Test
Strategy: from a formula to the possible structures: Count the rings and double bonds of a formula first. Then draw the structures in order: the longest chain, then the shorter chains with a branch on each different carbon, without drawing one twice.
Strategy: from masses and percentages to a formula: To find a formula from percentages, change each percentage to moles, divide by the smallest, and read the ratio. To find it from burning, find the carbon in the carbon dioxide and the hydrogen in the water.
Strategy: comparing fuels by heat and carbon dioxide: To compare fuels, change the heat per mole into heat per gram by dividing by the molar mass. Then find the carbon dioxide for each megajoule of heat: each carbon atom of the fuel becomes one molecule of carbon dioxide. Methane gives the most heat per gram of the carbon fuels and the least carbon dioxide for the same heat. Hydrogen gives no carbon dioxide at all.