Question

A student received a sample of an unknown substance weighing 5 grams. After performing a series of measurements, they found that the sample contained 2.5 grams of pure calcium carbonate and an unknown amount of impurities. Using mass balance calculations, determine the weight and composition of the impurities in the sample.

Answer 1

To determine the weight and composition of the impurities in the sample, we can use the mass balance principle. The mass balance principle states that the total mass of the sample is equal to the sum of the masses of its individual components  in this case, calcium carbonate and impurities .Let's denote the mass of the impurities as x. According to the mass balance principle:Total mass of the sample = Mass of calcium carbonate + Mass of impurities5 grams = 2.5 grams + xNow, we can solve for x:x = 5 grams - 2.5 gramsx = 2.5 gramsSo, the weight of the impurities in the sample is 2.5 grams.To find the composition of the impurities, we can calculate the percentage of each component in the sample:Percentage of calcium carbonate =  Mass of calcium carbonate / Total mass of the sample  * 100Percentage of calcium carbonate =  2.5 grams / 5 grams  * 100Percentage of calcium carbonate = 50%Percentage of impurities = 100% - Percentage of calcium carbonatePercentage of impurities = 100% - 50%Percentage of impurities = 50%Therefore, the impurities in the sample weigh 2.5 grams and make up 50% of the sample's composition.