3. The elements phosphorus and oxygen react to give tetraphosphorus pentoxide according to the balanced equation: P4+5O2P4O10 Suppose you have 0.8251molP4. (a) How many moles of O2 are needed for complete reaction? (b) What mass of P4O16, in grams, can be produced? (The molar mass of P4O10 is 283.8892g/mol ). 4. Chromium metal reacts with dilute hydrochloric acid according to the following umbalanced equation: Cr(s)+HCl(aq)CrCl3(aq)+H2(g) Suppose you react 1.85g of chromium metal with excess dilute hydrochloric acid. (a) What mass of CrCl2, in grams, can be obtained? (b) What mass of hydrogen gas, in grams, can be obtained? (c) If only 4.48g of CrCl is obtained, what is the percentage yield? Formula weight: CrCl1158.3542g/mol