A chemist mixes together 0.450 mol N2 with 0.450 mol H2 in a sealed container. The mixture is heated and allowed to reach equilibrium. At equilibrium, the mixture contains 0.400 mol N2 and the total pressure is 500 kPa. Calculate Kp.

balanced equation:  N2 (g) + 3H2 (g) <---> 2NH3 (g)  Both reactants and products are gases, therefore it affect Kp value. This equation reaches equilibrium as it is in a "sealed container", also known as closed system. steps to find Kp:  1) Find the mole of reactants and product at equilibrium: From the stoichiometry equation, we can tell that 3 mol of Hydrogen is needed for every 1 mol of nitrogen. This means that for every 0.450 mol of N2, 1.35 mol of H2 is needed. Since we only have 0.450 mol of hydrogen, we can tell that hydrogen is the limiting reagent. 2) Draw a table to find equilibrium moles.                      d                      N      3H2      2NH3 Initial mole/ mol        0.450    0.450     0.000 Reacting mole/ mol     -0.050   -0.150    +0.100 Equilibrium mole/ mol    0.400     0.300     0.100 3) Calculate partial pressure for each of these 3 gases: N2= (0.4/ 0.8) X 500 kPa= 250 kPa H2= (0.3/0.8) X 500 kPa= 187.5 kPa NH3= (0.1/0.8) X 500kPa= 62.5 kPa 4) place this partial pressure into Kp equation: Kp = (PNH) / (PH2 ) (PN2 ) Kp= 2.37 X 10-6 kPa 

NG

Related Chemistry A Level answers

All answers ▸

An unknown gas from a reaction is contained in a 2 litre beaker, at standard atmospheric pressure and a Temperature of 25 Celsius. Calculate the number of moles of the gas.


Explain the trend in ionisation energies for the group one metals?


Alcohols can be converted into alkenes in an elimination reaction. The elimination of H2O from pentan-2-ol forms a mixture of organic products. Give the names and structures of all the organic products in the mixture.


What is the meaning of the term 'structural isomers'?