Answer: 2 molecules of ammonia
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
The balanced chemical equation for the formation of ammonia is:

According to stoichiometry,
3 molecules of hydrogen combines with 1 molecule of nitrogen to give 2 molecules of ammonia.
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
The answer to that is mass and chemical