During a nuclear explosion, one of the products is 90Sr with a half-life of 28.1 years. If 1µg of 90Sr was absorbed in the bones of a newly born baby instead of calcium, the amount of 90Sr that will remain after 10 years in the now grown up child would be -
(Given ,antilog(0.108)=1.28)
1. 0.227 µg
2. 0.781 µg
3. 7.81 µg
4. 2.27 µg
For a reaction, 2A + B → C + D, the following observations were recorded:
Experiment | [A]/mol L–1 | [B]/mol L–1 | Initial rate of formation of D/mol L–1 min–1 |
I | 0.1 | 0.1 | 6.0 × 10–3 |
II | 0.3 | 0.2 | 7.2 × 10–2 |
III | 0.3 | 0.4 | 2.88 × 10–1 |
IV | 0.4 | 0.1 | 2.40 × 10–2 |
The rate law applicable to the above mentioned reaction would be:
1. Rate = k[A]2[B]3
2. Rate = k[A][B]2
3. Rate = k[A]2[B]
4. Rate = k[A][B]
t/s | 0 | 30 | 60 | 90 |
[Ester]/mol L–1 | 0.55 | 0.31 | 0.17 | 0.085 |
The rate equation of a reaction is expressed as, Rate = \(k(P_{CH_{3}OCH_{3}})^{\frac{3}{2}}\)
(Unit of rate = bar min–1)
The units of the rate constant will be:
1. bar1/2 min
2. bar2 min–1
3. bar–1 min–2
4. bar–1/2 min–1
The decomposition of NH3 on a platinum surface is a zero-order reaction. The rates of production of N2 and H2 will be respectively:
(given ; k = 2.5 × 10–4 mol–1 L s–1 )
1. | 2.5 × 10−4 mol L−1 s−1 and 5.5 × 10−4 mol L−1 s−1
|
2. | 2.5 × 10−4 mol L−1 s−1 and 7.5 × 10−4 mol L−1 s−1
|
3. | 1.5 × 10−4 mol L−1 s−1 and 4.5 × 10−4 mol L−1 s−1
|
4. | 0.5 × 10−4 mol L−1 s−1 and 3.5 × 10−4 mol L−1 s−1 |
If at a given instant, for the reaction 2N2O5 → 4NO2 + O2 rate and rate constant are 1.02 × 10-4 and 3.4 × 10-5 sec -1 respectively, then the concentration of at that time will be:
1. 1.732
2. 3.0
3.
4.
Select the correct option based on statements below:
Assertion (A): | The enthalpy of reaction remains constant in the presence of a catalyst. |
Reason (R): | A catalyst participating in the reaction forms a different activated complex and lowers down the activation energy but the difference in energy of the reactant and the product remains the same. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | Both (A) and (R) are False. |
Assertion (A): | Order and molecularity are the same. |
Reason (R): | Order is determined experimentally, and molecularity is the sum of the stoichiometric coefficient of the rate-determining the elementary step. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | (A) is False but (R) is True. |
Match the items in Column I and Column II:
Column I | Column II | ||
A. | Mathematical expression for the rate of reaction | 1. | Rate constant |
B. | Rate of reaction for zero-order reaction is equal to | 2. | Rate law |
C. | Units of rate constant for zero-order reaction is same as that of | 3. | Order of slowest step |
D. | Order of a complex reaction is determined by | 4. | Rate of reaction |
Codes:
A | B | C | D | |
1. | 3 | 4 | 1 | 2 |
2. | 1 | 2 | 3 | 4 |
3. | 2 | 1 | 4 | 3 |
4. | 4 | 1 | 3 | 2 |
Column I | Column II | ||
A. | Catalyst alters the rate of reaction | 1. | Proper orientation is not there always |
B. | 2. | By lowering the activation energy | |
C. | Energetically favorable reactions are sometimes slow | 3. | Total probability is one |
D. | Area under the Maxwell-Boltzmann curve is constant | 4. | Refers to the fraction of molecules with energy equal to or greater than the activation energy |
Codes:
A | B | C | D | |
1. | 2 | 4 | 1 | 3 |
2. | 3 | 1 | 4 | 2 |
3. | 1 | 4 | 3 | 2 |
4. | 3 | 4 | 1 | 2 |