Iron can form two sulfides: FeS and Fe₂S₃. Use Dalton's law of multiple proportions to predict the ratio of the two masses of sulfur that combine with 100 g of iron in each case to form these compounds.

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According to Dalton's law of multiple proportions, when two elements can form more than one compound, the ratios of masses of the second element that combine with a fixed mass of the first element can be expressed in small whole numbers. Let x be the mass of sulfur that combines with 100 g of iron to form FeS. Then, the mass of sulfur that combines with 100 g of iron to form Fe₂S₃ is (2x + 32) g (since this compound has two sulfur atoms per formula unit). We can set up the following equation based on the law of multiple proportions: x/(32 + x) = (2x + 32)/((32 + 2x) + (32 + x)) Solving for x, we get: x = 64 g Therefore, the ratio of masses of sulfur that combine with 100 g of iron to form FeS and Fe₂S₃ is: 64 g : (2(64 g) + 32 g) = 64 g : 160 g = 2 : 5 Simplifying this ratio by dividing both sides by 2, we get: 1 : 2.5 The closest choice to this ratio is D) 2:3.

Iron Can Form Two Sulfides: FeS and Fe2S3

Iron Can Form Two Sulfides: FeS and Fe₂S₃