Urea (CH4N2O) is a common fertilizer that can be synthesized by the reaction of ammonia (NH3) with carbon dioxide as follows: 2NH3(aq)+CO2(aq)→CH4N2O(aq)+H2O(l) In an industrial synthesis of urea, a chemist combines 142.1 kg of ammonia with 211.4 kg of carbon dioxide and obtains 171.4 kg of urea. Part A Determine the limiting reactant. Express your answer as a chemical formula.