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Grazes
A covalent compound with an empirical formula of P2X5 and a mass of 14.2g contains 8 grams of unknown element X. What is molar mass of X?
If there are 8 grams of X, then there are 6.2 grams of P, which is 0.2 moles. Using a ratio, we can see that there is 0.5 mol of X, so 1 mol would be 16 g. X is oxygen (O)