A 0.625 g of paracetamol powder with a uniformly sized particles was dissolved in 1000 ml of water. The dissolution data are found in the table below.

Determine the value of k, the cube-root dissolution rate constant, at each time interval and calculate the average value of K.

T(hr)

Concent. Drug release mg/ml

Amount drug release Mg/1lt Wt

0

159

Amount of undissolved drug Mt-625-Wt

0

0

0.159

466

4

0.288

0.39

288

337

6

8

390

235

0.468

0.528

468

157

10

528

97