how many grams of hydrogen are needed to completely react with 8 moles of nitrogen from this equation N2+H2=NH3

Balance the equation.

N2 + 3H2 ==> 2NH3
Using the coefficients in the balanced equation, convert mols N2 to mols H2. Then convert mols H2 to g. g = mols x molar mass.

To determine the number of grams of hydrogen needed to react with 8 moles of nitrogen, we first need to find the mole ratio between hydrogen and nitrogen from the balanced equation. The balanced equation is:

N2 + H2 = 2NH3

From the equation, we can see that one mole of nitrogen reacts with three moles of hydrogen to produce two moles of ammonia. This means the mole ratio of hydrogen to nitrogen is 3:1.

Now, we can use this information to calculate the amount of hydrogen needed. Since we know that there are 8 moles of nitrogen, we can multiply this by the mole ratio to find the moles of hydrogen needed:

8 moles of nitrogen x (3 moles of hydrogen / 1 mole of nitrogen) = 24 moles of hydrogen

Finally, to convert moles of hydrogen to grams, we need to use the molar mass of hydrogen, which is 1 g/mol. Therefore:

24 moles of hydrogen x 1 g/mol = 24 grams of hydrogen

So, 24 grams of hydrogen are needed to completely react with 8 moles of nitrogen.