Advertisements
Advertisements
प्रश्न
Radioactive decay follows first-order kinetics. The initial amount of two radioactive elements X and Y is 1 gm each. What will be the ratio of X and Y after two days if their half-lives are 12 hours and 16 hours respectively?
Advertisements
उत्तर
For first-order reaction
half life of X = 12 hours
2 days = 48 hours means 4 half lives,
Amount of X left = `1/16` of initial value
half life of Y = 16 hours
2 days = 48 hours means 3 half lives,
Amount left = `1/8` of initial value
Ratio of X : Y = 1 : 2
APPEARS IN
संबंधित प्रश्न
A first order reaction has a rate constant 1.15 × 10−3 s−1. How long will 5 g of this reactant take to reduce to 3 g?
Following data are obtained for reaction :
N2O5 → 2NO2 + 1/2O2
| t/s | 0 | 300 | 600 |
| [N2O5]/mol L–1 | 1.6 × 10-2 | 0.8 × 10–2 | 0.4 × 10–2 |
1) Show that it follows first order reaction.
2) Calculate the half-life.
(Given log 2 = 0.3010, log 4 = 0.6021)
A first order reaction is 50% completed in 1.26 × 1014 s. How much time would it take for 100% completion?
The rate constant of a first order reaction is 6.9 × 10–3s–1. How much time will it take to reduce the initial concentration to its 1/8th value?
A first order reaction is 50% complete in 20 minute What is rate constant?
The decomposition of formic acid on gold surface follows first-order kinetics. If the rate constant at 300 K is 1.0 × 10−3 s−1 and the activation energy Ea = 11.488 kJ mol−1, the rate constant at 200 K is ______ × 10−5 s−1. (Round off to the Nearest Integer)
(Given R = 8.314 J mol−1 K−1)
A definite volume of H2O2 undergoing spontaneous decomposition required 22.8 c.c. of standard permanganate solution for titration. After 10 and 20 minutes respectively the volumes of permanganate required were 13.8 and 8.25 c.c. The time required for the decomposition to be half completed is ______ min.
How will you represent first order reactions graphically?
The following data were obtained during the decomposition of SO2Cl2 at the constant volume. SO2Cl2 →SO2(g) + Cl2(g)
| Time (s) | Total Pressure (bar) |
| 0 | 0.5 |
| 100 | 0.6 |
Calculate the rate constant of the reaction.
If the half-life (t1/2) for a first order reaction is 1 minute, then the time required for 99.9% completion of the reaction is closest to ______.
