# How many grams of hydrogen are necessary to react completely with 50.0 g of nitrogen in the reaction #N_2+3H_2->2NH_3#?

##### 2 Answers

10.80 g of

#### Explanation:

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

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;

See below..

#### Explanation:

Assume that:

n = number of moles

m = mass of substance

M = molar mass (equivalent to atomic weight on the periodic table)

The mass (m) of

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

Now you need to calculate the number of moles (n) for nitrogen. If you refer back to the formula "

The number of moles (n) for nitrogen is:

[

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

Since the mole ratio between

If 1 mole of

then 1.785714286 moles of

[

Now you know the number of moles for

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

Once you've make m as the subject, the formula will look

The mass (m) of hydrogen is:

[

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.