When 476.58 grams of H2 are produced, 20074 grams of Mn were reacted. What is the percent yield of this reaction?
Mn + H2SO4 → → MnSO4 + H2

in the given question, the partial pressure is calculated by using the ideal gas equation, that is, pv = nrt

here, p is pressure, v is volume = 25 l, n is number of moles = 0.0104 moles, r is gas constant = -0.0821 l.atm / mol.k

t is temperature = 273 k

p = nrt / v

p = (0.0104 mol × 0.0821 l.atm / mol.k × 273 k) / 25 l

= 0.0093 atm

it means there are 3 atoms of oxygen

it is b that is the answer.