Answer:
0.133 mol (corrected to 3 sig.fig)
Explanation:
Take the atomic mass of H=1.0, and O=16.0,
no. of moles = mass / molar mass
so no. of moles of H2O produced = 1.2 / (1.0x2+16.0)
= 0.0666666 mol
From the equation, the mole ratio of H2:H2O = 2:2 = 1:1,
meaning every 1 mole of H2 reacted gives out 1 mole of water.
So, the no, of moles of H2 required should equal to the no, of moles of H2O produced, which is also 0.0666666 moles.
mass = no. of moles x molar mass
hence,
mass of H2 required = 0.066666666 x (1.0x2)
= 0.133 mol (corrected to 3 sig.fig)
