Chemistry gas question?

Question

A balloon was filled with 4800cm^3
the loss of hydrogen gas during filling was 20%. what mass of iron splints and 98% (by mass) H2SO4 were needed to ensure the complete filling of the balloon? assume temperature of 0 degrees C. a pressure of 1.0 atm and 100% yield.

Fe(s)+H2SO4 -----> FeSo4 (aq) + H2 (g)

how do you solve this?

Answer 1

I take it that we are to supply H2 to fill the balloon after the initial filling and loss. That loss is 960 cc. Assuming that 20% of the refill will also be lost, the H2 requirement is 960/.8=1200 cc.

Now we convert this to moles PV=nRT and n=0.55 moles appx. From the reaction, to obtain 0.55 moles of H2, 0.55 g-atom of iron and 0.55 moles of acid are needed. Mult 0.55 by atomic wt of iron, and by the mol wt of H2SO4/.98 to get the two masses.