The answers are VH2=43.1L and VCO=21.5L.
Starting from the ideal gas law PV=nRT and from the chemical reaction's balanced equation
CO(g)+2H2(g)→CH3OH(g), one can see that we get a 1:1 mole ratio for CO and CH3OH, and a 2:1 mole ratio forH2 and CH3OH.
The number of moles of CH3OH can be calculated from
nCH3OH=mCH3OH32gmol=25.8g32gmol=0.81 moles.
Subsequently, the number of moles for CO and H2 are
nCO=0.81 moles, and nH2=1.62 moles.
Therefore, the volume of H2 required for the reaction to take place is
VH2=nH2RTP=1.62⋅0.082⋅319.15748760=43.1 L ( I've converted pressure into atm anddegrees Celsius into K).
The volume of CO required will be
VCO=nCORTP=0.81⋅0.082⋅319.15748760=21.5 L, which is approximately half of the volume of H2 determined (half the number of moles -> half the volume);