Atomic Mass Of Ammonia

How to find the Molecular Weight for NH3: a step-by-step video tutorial. Using the Periodic Table look up the atomic weight of each of the elements in NH3. Ammonia NH3 Molar Mass, Molecular Weight. NH3 is a colorless gas with a pungent smell at room temperature. Its melting point is -77.73 ̊C (-107.914 ̊F), boiling point -33.34 ̊C (-28.012 ̊F).

Atomic Mass Of Chlorine Element
Mr Ammonia

Problem: What is the molar mass of ammonia, NH3? FREE Expert Solution. Calculate the molar mass of NH 3: The atomic mass of N is 14.01 g/mol and that of H is 1.01 g/mol. We multiply each atomic mass by the number present in the chemical formula and then add them together to get the molar mass. Molybdenum has an atomic number of 42. Several common isotopes exist, with mass numbers from 92-100. Therefore, which of the following can be true? A) Molybdenum atoms can have between 50 and 58 neutrons. B) Molybdenum atoms can have between 50 and 58 protons. C) Molybdenum atoms can have between 50 and 58 electrons.

What is the molar mass of ammonia, #'NH'_3#?

1 Answer

Atomic Mass Of Chlorine Element

Explanation:

To determine the molar mass of any compound, all you have to do is add up the molar masses of every atom that makes up the respective compound.

In this case, you know that ammonia, #'NH'_3#, is composed of

one nitrogen atom, #'N'#
three hydrogen atoms, #'H'#

This means that its molar mass will be the sum of the molar mass of one nitrogen atom and three times the molar mass of a hydrogen atom.

A quick look in the periodic table will show that you have

#'N: ' '14.0067 g/mol'#
#'H: ' '1.00794 g/mol'#

The molar mass of ammonia will thus be

#'14.0067 g/mol' + 3 xx '1.00794 g/mol' = color(green)('17.03052 g/mol')#

Mr Ammonia

Dalton atomic weights

John Dalton is remembered today for a remarkably fruitful atomic theory. The theory was not correct in every respect; however, it was a pivotal advance in chemistry because it had consequences that could be tested by experiment. Consider a testable prediction based on the following sets of atomic weights: predict the mass ratio of oxygen to nitrogen in 'nitrous gas' if the formula is NO.

1a) In the atomic weight scale Dalton began to construct, the atomic weights assigned to nitrogen ('azote') and oxygen were 5 and 7 respectively. Use these atomic weights to predict the O:N mass ratio in NO.
b) Now suppose Dalton had had accurate analyses of water and ammonia available in setting up his system of atomic weights. Dalton decided to use hydrogen as the unit for his system of atomic masses. By weight, the ratio of oxygen to hydrogen in water is 7.94:1 and the ratio of nitrogen to hydrogen in ammonia is 4.63:1. Since Dalton assumed that the formulas of water and ammonia were HO and NH respectively, he would have supposed that the atomic weights of oxygen and nitrogen were 7.94 and 4.63, respectively. Use these atomic weights to predict the O:N mass ratio in NO.
c) Use the atomic weights of nitrogen and oxygen from a modern table to predict the O:N mass ratio in NO. This is the result that an accurate analysis would obtain.

Summary of atomic weights of H, N, and O used in exercise 1.

source	H	N	O
a. Dalton 1808	1	5	7
b. 'Daltonesque'	1	4.63	7.94
c. modern	1.008	14.007	15.999

2) Finally, the chemical analyses to which Dalton had access put the O:N mass ratio in NO between 1.15:1 and 1.36:1 . Should Dalton have seen an inconsistency in the weights for H, N, and O of part 1a? What if he had used the weights of exercise 1b: should he have seen an inconsistency there? Explain.

Reference

Back to the Classic Calculations home page

Back to the top of the Classic Chemistry site