Question

Using the equation

N2+3H2-->2NH3

how many grams of hydrogen must react if the reaction needs to produce 31.75 grams of NH3?

Question options:

5.6


11.2


none of these


22.4

Answer 1

To produce 31.75 grams of NH3, 2.83 grams of hydrogen must react.

Step-by-step explanation:

To find the number of grams of hydrogen that must react to produce 31.75 grams of NH3, we need to use the stoichiometry of the balanced chemical equation. The equation shows that 3 moles of H2 react to produce 2 moles of NH3.

First, calculate the moles of NH3 produced using the given mass of NH3:

31.75 g NH3 x (1 mol NH3/ 34.08 g NH3) = 0.93 mol NH3

Then, use the mole ratio from the balanced equation to find the moles of H2 required:

0.93 mol NH3 x (3 mol H2/2 mol NH3) = 1.40 mol H2

Finally, convert the moles of H2 to grams:

1.40 mol H2 x (2.02 g H2/1 mol H2) = 2.83 g H2

Answer 2

(Answer) 5.6 g

Mass of ammonia produced = 31.75 g

Moles of ammonia produced = (Mass / molar mass of ammonia)

= ( 31.75 g / 17.031 g / mol) = 1.86 moles.

According to the balanced chemical equation, mole ratio of hydrogen and ammonia = 3: 2

Moles of hydrogen needed to produce 1.86 moles of ammonia

= (3/2 x 1.86 ) moles = 2.79 moles

Mass of hydrogen needed = ( Moles x molar mass of hydrogen)

= (2.79 x 2)g = 5.58 g = 5.6 g

Therefore, 5.6 g of hydrogen must react to produce 31.75 g of ammonia.