This may help you
<span>You need to use some stoichiometry here. The only way to do that is if you're working in moles. Since you're given grams of Al, you can convert that moles by dividing by the molar mass.
Then from looking at the coefficients in your equation, you can see that for however many moles of Al react, the same numbers of moles of Fe will be produced, but only half as many moles of Al2O3 will be produced.
To go back to grams, multiply the moles of each product that you get by their molar masses!</span>
The atomic mass would be 28.08535 amu. Multiply 27.9769 by .92297 = 25.803. Multiply 28.9765 by .046832 to get 1.357. Multiply 29.9738 by .03872 to get .925351136. Add 25.803 + 1.357 + .03872 to get 28.08535 amu
<span>The balanced reaction that describes the reaction between hydrogen and nitrogen to produce ammonia is expressed 3H2 + N2 = 2NH3. The yield of the reaction is equal to the actual amount of product divided to the theoretical amount of product multiplied by 100 percent. 26.3 grams of H2 theoretically produces149 grams. The yield is 79 divided by 149 equal to 53.02 percent. </span>
