InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
Calculate EMS velocity of oxygen at 0°C |
| Answer» <p>The answer for this question is 46140 cm/s</p> <p>Gases consist of atoms or molecules that move at different speeds in random directions. The root mean square velocity (RMS velocity) is a way to find a single velocity value for the particles.The average velocity of gas particles is found using the root mean square velocity formula</p><p>μrms= (3RT/M)½</p><p>whereμrms= root mean square velocity in m/secR= ideal gas constant= 8.3145 (kg·m2/sec2)/K·molT =absolute temperaturein KelvinM = mass of a mole of the gas inkilograms.</p><p>Really, the RMS calculation gives youroot mean square speed, not velocity. This is because velocity is a vector quantity, which hasmagnitude and direction. The RMS calculation only gives the magnitude or speed.</p><p>The temperature must be converted to Kelvin and the molar mass must be found in kg to complete this problem.</p><p>Step 1Find the absolute temperature using the Celsius to Kelvin conversion formula:</p><p>T = °C + 273T = 0 + 273T = 273 K</p><p>Step 2Find molar mass in kg:</p><p>From theperiodic table, molar mass ofoxygen= 16 g/mol.</p><p>Oxygen gas(O2) is comprised of two oxygen atoms bonded together. Therefore:</p><p>molar massof O2= 2 x 16molar mass of O2= 32 g/mol</p><p>Convert this to kg/mol:</p><p>molar mass of O2= 32 g/mol x 1 kg/1000 gmolar mass of O2= 3.2 x 10-2kg/mol</p><p>Step 3- Find μrms</p><p>μrms= (3RT/M)½μrms= [3(8.3145 (kg·m2/sec2)/K·mol)(273 K)/3.2 x 10-2kg/mol]½μrms= (2.128 x 105m2/sec2)½μrms= 461 m/sec</p><p>Answer:</p><p>The average velocity or root mean square velocity of a molecule in a sample of oxygen at 0 °C is 461 m/sec.</p> | |