Question

What volume of H2 gas (in L), measured at 750 mmHg and 90 ∘C, is required to synthesize 24.6 g CH3OH?

Answer 1

The balanced equation is

CO (g)   +   2 H₂ (g) ------ > CH₃OH (g)

number of moles of CH3OH = 24.6 g / 32.04 g/mol = 0.768 mole

from the balanced equation we can say that

1 mole of CH3OH requires 2 mole of H2 so

0.768 mole of CH3OH will require

= 0.768 mole of CH3OH *(2 mole of H2 / 1 mole of CH3OH)

= 1.54 mole of H2

PV = nRT

P = 750 mmHg = 0.987 atm

T = 273 + 90 = 363 K

0.987 * V = 1.54 * 0.0821 * 363

0.987 * V = 45.9

V = 45.9 / 0.987 = 46.5 L

Therefore, the volume of H2 needed would be 46.5 L