How many grams of hydrogen are necessary to react completely with 50.0 g of nitrogen in the reaction N2+3H22NH3?

2 Answers

10.80 g of H2

Explanation:

As per the equation, let us calculate the mole ratio.

N2+3H22NH3

As per the equation one mole of nitrogen reacts with 1 mol of hydrogen.

In terms of mass. 28.01 g of nitrogen needs 3 mol of hydrogen or 6.048 g of hydrogen.

We can set up the ratio;

28.01 g oflN2 needs 6.048 g oflH2

1 g oflN2 needs 6.04828.01g oflH2

50.0 g oflN2 needs 6.048×50.028.01lg oflH2=10.80 g oflH2

Apr 26, 2016

See below..

Explanation:

Assume that:
n = number of moles
m = mass of substance
M = molar mass (equivalent to atomic weight on the periodic table)

n=m÷M

The mass (m) of N2 has been given to you: 50.0 grams.

You first need to find out the molar mass (M) of nitrogen. If you refer to your periodic table, the molar mass (M) of nitrogen is 14.0 g/mol.
Since there are two nitrogens (refer to equation - look carefully), the molar mass of N2 in this reaction is 28.0 g/mol.

Now you need to calculate the number of moles (n) for nitrogen. If you refer back to the formula "n=m÷M", you need to find n.
The number of moles (n) for nitrogen is:
[n=50.0÷28.0] = 1.785714286 moles.
Note: Don't round it off just yet because this is not the final answer - or you'll get inaccurate answer.

You next step is to determine the number of moles (n) for hydrogen (3H2).

Since the mole ratio between N2:H2 is 1 : 3, so,
If 1 mole of N2 gives you 3 moles of H2,
then 1.785714286 moles of N2 should give you:
[1.785714286×3] = 5.357142857 moles of H2.

Now you know the number of moles for H2.

The next step is to find out the molar mass (M) of Hydrogen. If you refer to your periodic table, you know that hydrogen's molar mass is 1.0 g/mol.

Since there are two hydrogens present the molar mass of hydrogen in this reaction is 2.0 g/mol.
(look at equation, carefully - there are 2, not 5 or 6 because the front number is only used for moles).

Your last step is to find out its mass (m).

If you refer back to the formula n=m÷M, you need to make (m) as the subject because you are finding the mass.
Once you've make m as the subject, the formula will look m=n×M.

The mass (m) of hydrogen is:
[m=5.357142857×2.0] = 10.7 grams.
Note that: this answer is rounded to 3 significant figures.

Therefore, 10.7 grams of Hydrogen are necessary to fully react with 50.0 grams of Nitrogen.