(A) 0.0005
As we know,
\(1\,cm^3=1\,ml\)
\(\therefore 11.2\,cm^3=11.2\,ml\)
The volume of 1 mole of any gas at STP contain = 22400 ml/mol
\(\therefore\) Number moles of hydrogen gas = \(\frac{11.2\,ml}{22400\,ml/mol}\)
= \(5\times10^{-4}\) moles or 0.0005 moles.