Question

For the reaction so3 + h2o h2so4, calculate the percent yield if 500. g of sulfur trioxide react with excess water to produce 575 g of sulfuric acid.

Answer 1

The %  yield  if  500 g of  sulfur trioxide  reacted  with  excess  water to   produce  575 g  of  sulfuric  acid is calculated using  the  below  formula


%  yield = actual  yield/ theoretical  yield  x100

actual  yield =575 grams
to  calculate  theoretical  yield
find the  moles  of SO3   used =mass/molar  mass
=  500g/   80 g/mol =6.25  moles

SO3+H2O=H2SO4
by   use of  mole ratio  of SO3  :  H2SO4 which  is 1:1  the moles of H2SO4  is  also=  6.25  moles

the theoretical  yield of H2SO4 is therefore =  moles /molar  mass
=  6.25  x98=  612.5 grams

%yield  is therefore= 575 g/612 g   x100=  93.9  %