PLS HELP!! Nitric acid is made by a sequence of reactions, shown below.
4NH3(g) +5O2(g) = 4NO(g) + 6H2O(g)

2NO(g) + O2(g) = 2NO2(g)

3NO2(g) + H2O(g) = 2HNO3(g)+ NO(g)

If the first reaction occurs with 96.2% yield, the second reaction occurs with a 91.3% yield and the third reaction proceeds with a 91.4% yield,
calculate the following:

(a) The grams of nitric acid produced from 1216 grams of ammonia.
(b) The percent yield for the overall process

from the 1st equation:

  4NH3                  4NO

  4 *(68)                 4*30

  1216                     X  mass of NO = 536.5 g

from the 2nd Equation

  2NO           2NO2

   2*30            2* 46

   536.5          x         mass of NO2 = 822.6 grams

from the 3rd Equation

  3NO2                         2HNO3

   3*(46)                           2* (63)

     822.6                             X                mass of nitric acid = 751.06 gram

b)  % yields = ( 96.2%* 91.3% *91.4%)= 80.3%