What is the average translational kinetic energy of molecules in a gas at temperature 27°C?
Correct answer: C. 6.21 x 10^-21 J
- A. 3.23 x 10^-21 J
- B. 4.11 x 10^-21 J
- C. 6.21 x 10^-21 J
- D. 7.71 x 10^-21 J
- E. 9.11 x 10^-21 J
Explanation
The average translational kinetic energy of molecules in a gas is given by the formula: K.E. = (3/2) kTWhere K.E. is the average translational kinetic energy, k is the Boltzmann constant (approximately 1.38 x 10^-23 J/K), and T is the temperature in Kelvin.The given temperature is 27°C, which must be converted to Kelvin by adding 273.15:T = 27°C + 273.15 = 300.15 KSubstituting these values into the formula gives:K.E. = (3/2) * (1.38 x 10^-23 J/K) * (300.15 K)= 6.21 x 10-21 JTherefore, the correct answer is 6.21 x 10-21 J. The other options result from errors in calculation or incorrect conversions.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Reaction Kinetics
Reaction kinetics relates reaction rate to concentration, temperature, surface area and catalysts. Questions cover rate laws, reaction order, rate constants, activation energy and the activated complex, including how a catalyst lowers the activation energy without changing the overall energy change or equilibrium position.
Practise Reaction Kinetics
573 free Reaction Kinetics MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Chemistry questions like this
Chemistry is on 14 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Reaction Kinetics questions
Drawing a graph between concentration change with time gives a:
Half-life period for a first order reaction is independent of
The rate of chemical reactions helps in designing industrial process which is:
If a process cannot be retracted in the backward direction by reversing the controlling factors. It is a/an:
What is the order of reaction if the unit of K is sec-1 ?
The rate constant "R" in the rate equation is the rate of reaction when n concentration of each of the reactant is: