How do I calculate the volume of a gas?

How do you calculate the volume of a gas given the temperature, pressure, and grams?

• The reaction is: 2NaOH(aq) + 2Al(s) + 6H2O(l) ---> 2NaAl(OH)4(aq) + 3H2(g) The question is: Calculate the volume of H2 formed at 23 degrees Celsius, and 1.00atm if 3.12 g ...show more

• Answer:

  First find the moles of aluminium. Mol (Al) = 3.12 / 27 = 0.11555... moles (From the raction eq'n this is equivalent to '2' molar ratios). mol(H) = 0.11555... x 3/2 = 0.17333... ( From reaction eq'n this is equivalent to '3' molar ratios). So in the Ideal Gas Eq'n substitute 'n' (moles) for 0.17333.... Using that standard Ideal Gas Eq'n data R = 8.413 T = 296 P = 100000 Pa Hence Vol(m^3) = 0.17333... x 8.314 x 296 / 100000 vol(m^3) = 0.0042656362666 m^3 vol(mL) = 0.00442656362666 / 10^6 = 4426.56 mL (cm^3) Or approximately 4.5 litres. Note the Ideal Gas Eq'n gives the resultant volume in 'cubic metres' - NOT litres NOR milli litres - you have to convert!!!!