Ammonium nitrate (NH4NO3) is an important agricultural industrial chemical as it provides readily available nitrogen for plant growth, and one can buy 50. pounds of ammonium nitrate for $38. Urea

Question

(CO(NH2)2) is an attractive alternative, and, not being a pre-cursor to an explosive, draws less attention from law enforcement when buying significant quantities.The key component is the nitrogen content (%composition) in the substance that feeds your plants. What will the price of urea be (for 50. Pounds) in order to provide the same amount of nitrogen per
dollar spent?

Answer 1

Calculate %N in NH4NO3.
Calculate %N in urea.
Those are done (mass N/molar mass compound)*100 = %N.

Then amount N in 50 lbs NH4NO3 = 50 lbs x (percent N/100) = ?
And 38/?amount N = cost/lb N.

Amount N in urea = 50 x (percent N/100) = ?
And X/?amount N = cost/lb N.