Map coa University Science Books presented by Sapling Learning ra Donald McQuanr
ID: 880604 • Letter: M
Question
Map coa University Science Books presented by Sapling Learning ra Donald McQuanrie Peter A. Rock Ethan Gallogy Phosphine, PH3(g), decomposes according to the equation Time (min) Ptotal (Torr) 0.00 40.0 80.0 100 100 151 168 P, g) + 6H The kinetics of the decomposition of phosphine at 950 K was followed by measuring the total pressure in the system as a function of time The data to the right were obtained in a run where the reaction chamber contained only pure phosphine at the start of the reaction Choose the rate law that describes this reaction. Calculate the value of the rate constant and choose the correct units rate = k Number Units Select answer PH3 rate = k(PP-')-2 rate = k(PPH ) rate = k(PPH)2 PH3 Previous Give Up & View Solution O Check Answer Next Exit HintExplanation / Answer
Plot graph of [P(PH3] vs time, ln[P(PH3)) vs time and 1/[P(PH3)) vs time, the one which gives straight line is the rate order. Here it is a first order reaction.
Thus, For the given reaction,
The rate law that describes this reaction would be,
rate = k(PPH3)
Calculation for the rate constant,
ln[Ao/A] = -kt
Taking the first two readings,
k = -ln(100/151)/40
k = 0.0103