(Solved): 3. The elements phosphorus and oxygen react to give tetraphosphorus pentoxide according to the bala ...

3. The elements phosphorus and oxygen react to give tetraphosphorus pentoxide according to the balanced equation: $${\mathrm{P}}_4+5{\mathrm{O}}_2?{\mathrm{P}}_4{\mathrm{O}}_{10}$$ Suppose you have $$0.8251\mathrm{mol}{\mathrm{P}}_4$$. (a) How many moles of $${\mathrm{O}}_2$$ are needed for complete reaction? (b) What mass of $${\mathrm{P}}_4{\mathrm{O}}_{16}$$, in grams, can be produced? (The molar mass of $${\mathrm{P}}_4{\mathrm{O}}_{10}$$ is $$283.8892\mathrm{g}/\mathrm{mol}$$ ). 4. Chromium metal reacts with dilute hydrochloric acid according to the following umbalanced equation: $$\mathrm{Cr}(\mathrm{s})+\mathrm{HCl}(\mathrm{aq})?{\mathrm{CrCl}}_3(\mathrm{aq})+{\mathrm{H}}_2(\mathrm{g})$$ Suppose you react $$1.85\mathrm{g}$$ of chromium metal with excess dilute hydrochloric acid. (a) What mass of $${\mathrm{CrCl}}_2$$, in grams, can be obtained? (b) What mass of hydrogen gas, in grams, can be obtained? (c) If only $$4.48\mathrm{g}$$ of $$\mathrm{CrCl}$$ is obtained, what is the percentage yield? Formula weight: $${\mathrm{CrCl}}_{1}158.3542\mathrm{g}/\mathrm{mol}$$