Answer to Question #76806 in Physical Chemistry for Tina

Question

a) For a reaction of the type:
A Products

t/ s 0 20 40 60 80
[A] / mol dm-3 0.964 0.689 0.492 0.352 0.251

By drawing an appropriate graph, deduce the order of the reaction and determine the value of the rate constant for the reaction at = 298 K.

b) i) At T=350 K, the root-mean-squared speed of the molecules in a gas is crms = 558 m-1Calculate the molar mass of the gas (in units of g mol—1).

ii) At what temperature is the root-mean-squared speed of the molecules in the gas equal to twice the value at = 350 K ?

C) i) A vessel of volume 16.8 dms contains 0.164 mol of oxygen gas at a temperature of 500 °C. Assuming ideal gas behaviour, calculate the pressure inside the vessel.

ii) An amount (0.088 mol) of krypton gas is then inserted into the vessel, with the original oxygen gas still present, and the temperature is raised to 700 °C. Assuming ideal gas behaviour, calculate the total pressure inside the vessel.