Mcquarrie 6 11 the results we derived for a rigid rotator...

. (McQuarrie 6-11) The results we derived for a rigid rotator apply to linear polyatomic molecules as well as to diatomic molecules. Given that the moment of inertia for H12C14N is 1.89×10-46kg*m2, predict the microwave spectrum of H12C14N.

Transcript

00:01 Hello students, in this question we are asked to calculate moment of inertia i for hcn molecule and also we need to calculate the rotational constant b.

00:12 The solution is as follows.

00:14 First we need to have bond lengths and masses of atoms.

00:18 Bond length of hc bond is 1 .06 angstrom, bond length for cn bond is 1 .16 angstrom, mass of 1h is 1 .67 into 10 power minus 27 kg, mass of c12 is 1 .99 into 10 power minus 26 kg, mass of n14 is 2 .32 into 10 power minus 26 kg.

00:41 This bond length and masses value are constant values.

00:46 Next we need to convert bond length to meters that is 1 .06 angstrom to 1 .06 into 10 power minus 10 meters.

00:59 Similarly 1 .16 angstrom equals 1 .16 into 10 to the power minus 10 meter.

01:07 Next we have to calculate moment of inertia.

01:10 Moment of inertia i is given by mu into r square where mu is the reduced mass, r is the distance between the atoms.

01:19 Now for a linear rotor like hcn, moment of inertia is given as the sum of moments of inertia for hc bond and cn bond that is i equal to mh into mc divided by mh plus mc into rhc square plus mc into mn divided by mc plus mn into rcn square.

01:43 Now plugging the values and calculating i, we have i equals 1 .67 into 10 to the power minus 27 kg into 1 .99 into 10 power minus 26 kg divided by 1 .67 into 10 to the power minus 27 plus 1 .99 into 10 to the power minus 26 kg into 1 .06 into 10 to the power minus 10 meter square plus 1 .99 into 10 to the power minus 26 kg into 2 .32 into 10 to the power minus 26 kg divided by 1 .99 into 10 to the power minus 26 plus 2 .32 into 10 to the power minus 26 kg into 1 .16 into 10 to the power minus 10 meter square.

02:56 Now on solving we get moment of inertia i approximately equal to 2 .33 into 10 to the power minus 46 kg meter square.

03:14 We got moment of inertia.

03:16 Now we have to calculate the rotational constant b...

Question

. (McQuarrie 6-11) ﻿The results we derived for a rigid rotator apply to linear polyatomic molecules as well as to diatomic molecules. Given that the moment of inertia for H12C14N ﻿is 1.89×10-46kg*m2, ﻿predict the microwave spectrum of H12C14N.

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. (McQuarrie 6-11) The results we derived for a rigid rotator apply to linear polyatomic molecules as well as to diatomic molecules. Given that the moment of inertia for H12C14N is 1.89×10-46kg*m2, predict the microwave spectrum of H12C14N.