Constants Part A Modern vacuum pumps make it easy to attain pressures of the ord
ID: 1574366 • Letter: C
Question
Constants Part A Modern vacuum pumps make it easy to attain pressures of the order of 10 13 atm in the laboratory You may want to review (Pages 590 -593) For related problemsolving tips and strategies, you may want At a pressure of 7.25 10-14 atm and an ordinary temperature of 294.0 K, how many molecules are present in a volume of 1.04 cm3 to view a Video Tutor Solution of Atomic and molecular mass Submit Request Answer Part B How many molecules would be present at the same temperature but at 1.05 atm instead? moleculcs Submit Request AnswerExplanation / Answer
A) given P = 7.25*10^-14 atm
= 7.25*10^-14*1.013*10^5
= 7.34*10^-9 pa
T = 294 K
V = 1.04 cm^3 = 1.04*10^-6 m^3
use, P*V = n*R*T
n = P*V/(R*T)
= 7.34*10^-9*1.04*10^-6/(8.314*294)
= 3.12*10^-18 moles
No of molecules present, N = n*Na
= 3.12*10^-18*6.023*10^23
= 1.88*10^6 molecules
B) n = P*V/(R*T)
= 1.05*1.013*10^5*1.04*10^-6/(8.314*294)
= 4.52*10^-5 moles
No of molecules present, N = n*Na
= 4.52*10^-5*6.023*10^23
= 2.72*10^19 molecules