Homework answers / question archive / Florida A&M University PHARMACY PHA 3102 Quiz 4 1)Determine the activation energy, Ea, for a reaction who's rate constant k1 = 8

Florida A&M University PHARMACY PHA 3102 Quiz 4 1)Determine the activation energy, Ea, for a reaction who's rate constant k1 = 8

Health Science

Share With

---

Florida A&M University

PHARMACY PHA 3102

Quiz 4

1)Determine the activation energy, Ea, for a reaction who's rate constant k1 = 8.9 x 10-3 s-1 at 3oC changes to k2 = 7.1 x 10-2 s-1 when the temperature is changed to 35oC. R = 1.987 cal K-1mol-1. Answer must be in kcal/mol.

2.            Determine the activation energy, Ea, for a reaction who's rate constant k1 = 4.600 x 10-5 s-1 at

364.00 Kelvin changes to k2 = 7.500 x 10-3 s-1 when the temperature is changed to 790 Kelvin. R

= 1.987 cal K-1mol-1. Answer must be in kcal/mol.

 

3.            Determine the activation energy, Ea, for a reaction who's rate constant k1 = 1.800 x 10-4 s-1 at

354.00   Kelvin changes to k2 = 5.200 x 10-3 s-1 when the temperature is changed to 652.00 Kelvin. R = 1.987 cal K-1mol-1. 

4.            If the half-life for decomposition of a drug is 12 hours, how long will it take for 125mg of the drug to decompose by 30%? Assuming first order kinetics and at a constant temperature:

•             3.3 hours

•             6.2 hours

•             9.8 hours

•             12.4 hours

•             15.6 hours

 

5.            If the amount of the drug in the body declines from 100% of the dose (IV bolus injections) to 15% of the dose in 24 hours, what is the elimination half-life for this drug? (assume first-order kinetics):

•             11 hours

•             14 hours

•             4 hours

•             6 hours

•             9 hours

 

6.            After the administration of a single IV dose (280mg) of theophylline to a patient, the drug

amount-time profile in this patient was assumed to follow zero-order kinetics with elimination rate constant of 0.12mg/hr. how long would it take for the amount of theophylline in the body to decrease to 0.5%?

•             2321.7 hours

•             96.74 days

•             15.82 weeks

•             A and B

•             A, B and C

 

7.            A drug has an elimination T1/2 of 6 hours and follows first-order kinetics. If a single 200mg dose is given to an adult male patient by IV bolus injection, what percent of the dose is lost in 24 hours? a. 99.9%

b.   94%

c.             85%

d.   54%

e.   20%

 

8.            If the amount of drug in the body declines from 100% of the dose (IV bolus injection) to 25% of the dose in 8 Hours, what is the elimination half-life for this drug? (assume first-order reactions)

•             0.173 hours

•             0.75 hours

•             2 hours

•             4 mins

•             240 mins

9.            A 65.8Kg woman was given a single IV dose (mg) of a new drug. Blood samples were taken at various time intervals. The amount of the drug was determined in the plasm fraction of each blood sample and the graph below was obtained with and equation y= -0.0947 + 1.0498

 

 

How long would it take for 99.09% of this drug to be eliminated?

•             5 mins

•             9 hours

•             21 mins

•             40 hours

•             47 mins

 

10.          A drug has an elimination T1/2 of 10 hours and follows zero-order kinetics. If a single 50mg dose is given to an adult male patient by IV bolus injection, what percent of the dose is lost in 14 hours?

•             54

•             70

•             85

•             94

e. 100

 

11.          If the amount of drug in the body declines from 100% of the dose (IV bolus injection) to 15% of the dose in 24 hours, what is the elimination half-life for this drug? (assume zero-order kinetics)

•             11 hours

•             14 hours

•             4 hours

•             6 hours

•             10 hours

 

12.          After the administration of a single IV dose (280mg) of theophylline to a patient, the drug amount-time profile in this patient was assumed to follow zero-order kinetics with elimination rate constant of 0.12mg/hr. how long would it take for the amount of theophylline in the body to decrease to 0.5%?

•             23221.7 hours

•             96.74 days

•             15.82 weeks

•             A and B

•             A, B and C

 

13.          If the amount of drug in the body declines from 100% of the dose (IV bolus injection) to 25% of the dose in 8 Hours, what is the elimination half-life for this drug? (assume first-order reactions)

•             0.173 hours

•             0.75 hours

 

•             2 hours

•             4 mins

•             240 mins

 

14.          A drug has an elimination T1/2 of 6 hours and follows first-order kinetics. If a single 200mg dose is given to an adult male patient by IV bolus injection, what percent of the dose is lost in 24 hours?

•             54

•             75

•             85

•             94

e. 100

 

15.          What us the concentration of drug remaining in systemic circulation after 4 hours, if the initial concentration is 16.2mg/L and elimination rate constant (Kel is 0.2hr-1 ) ? (assume first order process)

a.   7.27

b.   9.58

c.             12.24

d.   15.92

e. 25

 

16.          What is the initial concentration of drug if the drug concentration remaining in blood is 7.8 mg/L after 8hr and half-life is 2.475hr? (assume first order kinetics)

a.   20.5

b.   31.3

c.             52.67

d.   73.26

e.   83.78

 

17.          A 70-kg volunteer is given an intravenous dose of an antibiotic, and serum drug concentrations were determined at 1 hours and 6 hours after administration. The drug concentrations were 4.2 and 0.4 mg/mL, respectively. What is the half-life for this drug, assuming first-order elimination kinetics?

•             1.2 hours

•             1.5 hours

•             2.5 hours

•             4.0 hours

•             6.2 hours