Why the answer is C?
hi molar ratio H2 : Zn is 1 : 1 so 6 moles of H2 are produced by 6 moles of Zn m=n * Mw = 6 * 91 = 546g percent yield = 70% so out of our sample of Zn only 70% = 546g reacted 546 * 100 / 70 = 780g
