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2 years ago

Using a 300 MHz NMR instrument:

Chemistry

1 answer:

Softa [21]2 years ago

6 0

Answer:

a. 750Hz, b. 4.0ppm, c. 600Hz

Explanation:

The Downfield Shift (Hz) is given by the formula

Downfield Shift (Hz) = Chemical Shift (ppm) x Spectrometer Frequency (Hz)

Using the above formula we can solve all three parts easily

a. fspec = 300 MHz, Chem. Shift = 2.5ppm, 1MHz = 10⁶ Hz, 1ppm (parts per million) = 10⁻⁶

Downfield Shift (Hz) = 2.5ppm x 300MHz x (1Hz/10⁶MHz) x (10⁻⁶/1ppm)

Downfield Shift = 750 Hz

The signal is at 750Hz Downfield from TMS

b. Downfield Shift = 1200 Hz, Chemical Shift = ?

Chemical Shift = Downfield shift/Spectrometer Frequency

Chemical Shift = (1200Hz/300MHz) x (1ppm/10⁻⁶) = 4.0 ppm

The signal comes at 4.0 ppm

c. Separation of 2ppm, Downfield Shift = ?

Downfield Shift (Hz) = 2(ppm) x 300 (MHz) x (1Hz/10⁶MHz) x (10⁻⁶/1ppm) = 600 Hz

The two peaks are separated by 600Hz

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vladimir1956 [14]

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Explanation:

Given that:

Volume of gas V = 3.47L

(since 1 liter = 1dm3

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(85.0°C + 273 = 358K)

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pV = nRT

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p = (0.29 atm dm3 / 3.47 dm3)

p = 0.085 atm

Recall that pressure of the gas is required in mm hg, so convert 0.085 atm to mm Hg

If 1 atm = 760 mm Hg

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Explanation:

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Key Points

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