Question

OKINETICS AND EQUILIBRIUM Calculating the reaction rate of one reactant from that of another In the Haber reaction, patented by German chemist Fritz Haber in 1908, dinitrogen gas combines with dihydrogen gas to produce gaseous ammonia. This reaction is now the first step taken to make most of the world's fertilizer. Suppose a chemical engineer studying a new catalyst for the Haber reaction finds that 793. liters per second of dinitrogen are consumed when the reaction is run at 201. "C and 0.62 atm. Calculate the rate at which ammonia is being produced. Give your answer in kilograms per second. Be sure your answer has the correct number of significant digits. Y f 2

Answer 1

Relation between reaction rates of different species involved in a reaction : For the reaction : N2 + 3H2 —2NH3 Rate of reaction of N2 = - d[N2]. Rate of reaction of H2 = _ [42] dt Rate of reaction of NH3 = 0[NH3] dt These rates are not all equal. Therefore by convention the rate of a reaction is defined as Rate of reaction = _d[N2) = -1 d[H2] - 1 d[NH3] dt 3 dt 2 dt Note : Rate of reaction value is dependent on the stoichiometric coefficients used in the reaction while rate of any species will be fixed value under given conditions.

N2 + 3H210) Z DN Hg (a) I was thing V-Rate Vob2-793 4sec (consumed ] ๆ ชม. -% consumod = - 2x=793 Lsec YNHE = + 1583 l/sec So, Volume of NHz przoduced in 1sec 1/= 1583 2

Ideal gas equation, _ PV = nRT where, P-pressure (in aton) V 'Volume In LL I temperature link) n-mols of gas R- Universal gay cowstant R = 0.082) amm-! mol-k

T= 20100 = (2014273)* = 474 K p= 0.62 atm so, moty of NHg = pu= 0*62* 1583 hool [ 0.082, X474' 1. = 25.27 mol And mass of NH₂ = moles y molar mass = 25-27 x 17 gm/poot = 430gm 1. = 10.430 kg so, Rate of NH3 + 10.430 kg/sec (in kg/sec) L