Question

When vandium(V) oxide is reacted with hydrogen gas at elevated temperatures (155 degrees celsius and 1 atm), it produces vandium metal and water vapor in 92.4% yield. What mass of vandium(V) oxide and volume of hydrogen gas would be required to produce 11.3 grams of vandium under these conditions?

Answer 1

mass of V = 11.3 g

moles of V = 11.3 / 50.94 = 0.2218 mol

% yield = (actual / theoretical) x 100

92.4 = (11.3 / theoretical) x 100

theoretical yield = 12.23 g

V2O5         +   5 H2    -----------> 2 V   + 5 H2O

181.88 g           10 g                       101.88 g

   ??                                                  12.23 g

mass of V2O5 = 12.23 x 181.88 / 101.88

mass of V2O5 = 21.8 g

mass of H2 formed = 1.2 g

moles of H2 = 0.600 mol

P V = n R T

1 x V = 0.600 x 0.0821 x (155 + 273)

V = 21.1 L

volume of H2 = 21.1 L