Answer to Question #308428 in General Chemistry for Krix

Question

Solve the following stoichiometry grams-grams problems:

1) Using the following equation:

Pb(SO4)2 + 4 LiNO3 

Pb(NO3)4 + 2 Li2SO4

How many grams of lithium nitrate will be needed to make 250 grams of lithium sulfate,

assuming that you have an adequate amount of lead (IV) sulfate to do the reaction?

2) Using the following equation:

Fe2O3 + 3 H2 -------------> 2 Fe + 3 H2O

Calculate how many grams of iron can be made from 16.5 grams of Fe2O3 by the following

equation.

Answer 1

1)

$m(LiNO_3)=250\ g(Li_2SO_4)\times\frac{1\ mol(Li_2SO_4)}{109.94\ g(Li_2SO_4)}\times\frac{4\ mol(LiNO_3)}{2\ mol(Li_2SO_4)}\times\frac{68.94\ g(LiNO_3)}{1\ mol(LiNO_3)}=314\ g$

Answer: 314 g

2)

$m(Fe)=16.5\ g(Fe_2O_3)\times\frac{1\ mol(Fe_2O_3)}{159.69\ g(Fe_2O_3)}\times\frac{2\ mol(Fe)}{1\ mol(Fe_2O_3)}\times\frac{55.85\ g(Fe)}{1\ mol(Fe)}=11.5\ g$

Answer: 11.5 g