Question

Based on the activation energies and frequency factors, rank the following reactions from fastest to slowest reaction rate, assuming they are all at the same temperature and that each starts with the same initial concentration.

Rank from fastest to slowest reaction rate. To rank items as equivalent, overlap them.

temperature and that each starts with the same initial concentration. Rank from fastest to slowest reaction rate. To rank items as equivalent, overlap them. View Available Hint(s) Reset Help B = 60k) yuran B = 360 k/ml E =50 1/mol Ey = 50 kJ/mol Ey = 350 kJ/mol Ey = 50 kJ/mol Fastest Slowest The correct ranking cannot be determined. Submit

Fraction of molecules

The exponential term in the Arrhenius equation is equal to the fraction of molecules, f, with kinetic energy greater than or equal to the activation energy:

f=e−Ea/(R⋅T)

Most scientific calculators have an e^xfunction as the second function of the LN button.

Part B

A certain reaction with an activation energy of 155 kJ/mol was run at 475 K and again at 495 K . What is the ratio of f at the higher temperature to f at the lower temperature?

Express your answer numerically using one significant figure.

Answer 1

Activation energy is the minimum required energy to start a chemical reaction. Higher the activation energy lower will be the rate of a reaction. So the reaction with activation energy of 350 KJ/mol will have lowest reaction rate where as the reaction with 50 KJ/mol activation energy will have highest reaction rate.

Reaction Rate:

50 KJ/mol > 350 KJ/mol

Arrhenius Equalon, K= A e Eart The Activation energy t = Rate Const. A = Pre-exponential facto Faz tetivation Energy Ea ł kt heima Reaction Coordinale Fraction of molecule, Ea = 155 kJ/mol TAG = 495k T475 - 475k Eros = è E/RTRS ans = e Ed/8415 har & Fa/RTGAS e E/RT415 7495 - 3475 feas - tars to has - 155x10 495 / 475 7495 = e 8.314 +475

os taas 155x10² ( 495-475 pas = e 8.314 l 495x475 1 Hans Faas - ( 159 or 1475 +499 = 4.903 a 4.9. Ans 3475