Answer:
d. 1.2 × 1024
Explanation:
From the equation of reaction
2H2 + O2= 2H2O
i.e 2mole(4g) of hydrogen requires 1 mole(32g) of oxygen to produce 2mole (2×6.02×10^23 molecules) of H2O= 1.2×20^24 molcules of water.
NB: 1 mole of H2O contains 6.02×10^23 molecules of H2O