KINETICS AND DRUG STABLITY
TOP 10 MCQ
1. In terms of the kinetics degradation in suspension is [GPAT-2023 SHIFT-II]
(a) First order
(b) Second order
(c) Pseudo zero order
(d) Zero order
2. Efficiency of a reversible engine is given by [GPAT-2023 SHIFT-II]
(a) Clapeyron equation
(b) Clausius Clapeyron equation
(c) Gibbs-Helmholtz equation
(d) Carnot theorem
3. A sample of glucose was decomposed at 140°C in a solution containing 0.030M HCl. The velocity constant, k, was found to be 0.0080 hr⁻¹. If the spontaneous rate constant is 0.0010 hr⁻¹ and the catalysis due to hydroxyl ions in this acidic solution is considered as negligible, then the catalytic coefficient, KH is [GPAT-2023 SHIFT-II]
(a) 0.22 per mole per hour
(b) 0.233 per mole per hour
(c) 0.27 per mole per hour
(d) 0.29 per mole per hour
4. Which one of the following is a rate equation for second order bimolecular reaction if, a and b are the initial concentrations of A and B, respectively, and x is the concentration of each species reacting in time t and k is second-order rate constant [GPAT-2022]
(a) k = [2.303/(a − b)] × [log a(a − x) / b(b − x)]
(b) k = [2.303/(a − b)] × [log b(a − x) / a(b − x)]
(c) k = [2.303/(a − b)] × [log b(a − x) / a(b − x)]
(d) k = [2.303/(a − b)] × [log a(a − x) / b(b − x)]
5. Drugs ‘A’, ‘B’ and ‘C’ follow zero order, first order and second order degradation kinetics, respectively, but have the same rate constant. Which of the following statement is true in this respect [GPAT-2022]
(a) Drug ‘A’ will be the first to degrade by 50%
(b) Drug ‘B’ will be the first to degrade by 50%
(c) Drug ‘C’ will be the first to degrade by 50%
(d) Drugs ‘B’ and ‘C’ will degrade by 50% at the same time
6. The initial concentration of a drug decomposing according to first order kinetics is 28 units/mL. The specific decomposition rate, k, obtained from an Arrhenius plot is 2.09 × 10⁻⁵ hr⁻¹ at room temperature 25°C. Previous experimentation has shown that when the concentration of the drug falls below 15 units/mL it is not sufficiently potent for use and should be removed from the market. What expiration date should be assigned to this product [GPAT-2021]
(a) Approximately 31,012.15 hours
(b) Approximately 32,225.56 hours
(c) Approximately 27,216.12 hours
(d) Approximately 29,869.23 hours
7. Kinetically 1 / a(a − x) kT is the expression for [GPAT-2019]
(a) First order reaction
(b) Second order reaction
(c) Pseudo first order reaction
(d) Fractional order reaction
8. Which equation is used to predict the stability of a drug product at room temperature from experiments at accelerated temperature [GPAT-2018]
(a) Higuchi equation
(b) The Arrhenius equation
(c) Hildebrand equation
(d) The Hixson-Crowell equation
9. Which of the following formula is used to determine shelf life as per first order reaction [GPAT-2018]
(a) t90 = 0.693 / k
(b) t90 = 0.104 / k
(c) t1/2 = 0.693 / k
(d) t1/2 = 0.105 / k
10.Units for rate constant (K) for second order kinetics [GPAT-2015]
(a) S⁻¹
(b) Moles/liter · S
(c) Moles/liter · S⁻¹
(d) Moles · liter⁻¹ · S⁻¹
ANSWER KEY
| 1-d | 2-d | 3-b | 4-b | 5-c | 6-d | 7-b | 8-b | 9-d | 10-c |
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