What is the mole ratio of PbO2 to water?

PbO, H,0 = 1:0

The mole ratio of PbO2 to H2O is 1 : 2.

Explanation:

The balanced reaction equation is:

Pb + PbO2 + 2H2SO4 → 2PbSO4 + 2H2O

On the reactant side, we have 1 mole of Pb, 1 mole of PbO2, 2 moles of H2SO4.

On the product side, we have 2 moles of PbSO4 and 2 moles of H2O.

This means that for ever 1 mole of PbO2 consumed, 2 moles of water is formed as product.

Hence, the mole ratio of PbO2 to H2O is 1 : 2.

n2(g) + 3h2-> 2nh3(g)   this is the balanced equation

note the mole ratio between n2, h2 and nh3.   it is 1 : 3 : 2   this will be important.

moles n2 present = 28.0 g n2 x 1 mole n2/28 g = 1 mole n2 present

moles h2 present = 25.0 g h2 x 1 mole h2/2 g = 12.5 moles h2 present

based on mole ratio, n2 is limiting in this situation because there is more than enough h2 but not enough n2.

moles nh3 that can be produced = 1 mole n2 x 2 moles nh3/mole n2 = 2 moles nh3 can be produced

grams of nh3 that can be produced = 2 moles nh3 x 17 g/mole = 34 grams of nh3 can be produced

note:   the key to this problem is recognizing that n2 is limiting, and therefore limits how much nh3 can be produced.