NTA Abhyas NEET2020ChemistryChemical KineticsPractice
The reaction A g → B g + 2 C g is a first-order reaction with a rate constant of 2.303 x 10 -3 s -1 . Starting with 0.1 moles of 'A' in a 2 litre vessel, find the concentration of A after 301 sec when the reaction is allowed to take place at constant pressure at 300 K.
Options
- A0.0125 M
- B0.025 M
- C0.05 M
- DNone of these
Correct answer
B. 0.025 M
Step-by-step solution
t 1 / 2 = 0 . 6 9 3 2 . 3 0 3 × 1 0 - 3 = 6 9 3 2 . 3 0 3 = 3 0 1 sec initial concentration = moles of A/volume = 0.1/2 = 0.05 mole/L i.e., after t 1 /2 , no. of moles of 'A' reacted is half the initial moles. Final conc. of [A] = 0.05/2 = 0.025 M