Answer
The volume of hydrogen gas that is formed is $27.658 L$
Work Step by Step
$1C_{(s)} + 1H_{2}O_{(g)} --> 1CO_{(g)} + 1H_{2}._{(g)}$
Since the balanced equation shows a 1:1:1:1 mole ratio between all species, 1.07 moles of $C$ is equivalent to 1.07 moles of $H_{2}$
Now, using the ideal gas law $PV = nRT$ where "P" is the pressure the gas exerts, "V" is the volume the gas occupies, "n" represents the number of moles of the gas, "R" is the ideal gas constant and "T" represents the temperature, we can solve many gaseous questions that behave in ideal conditions.
The question asks for $V$ so we must isolate for the volume from the ideal gas equation to obtain $V = \frac{nRT}{P}$
$V = \frac{1.07 mols \times 0.08206 \frac{L\times atm}{mol\times K} \times 315 K}{1.0 atm} = 27.658 L $
