If 42 g of nitrogen reacts completely with 9 g of hydrogen (atomic mass 1) to form ammonia (NH₃), the atomic mass of nitrogen must be A) 55. B) 3. C) 49. D) 52. E) 14.

Question

Quizplus · Accepted Answer

First, we need to write the balanced chemical equation for the formation of ammonia:

N2 + 3H2 → 2NH3

From the equation, we can see that 1 mole of N2 reacts with 3 moles of H2 to produce 2 moles of NH3.

Let's find out how many moles of H2 we have:

mass of H2 = 9 g
molar mass of H2 = 2 g/mol
number of moles of H2 = mass/molar mass = 9/2 = 4.5 mol

According to the balanced chemical equation, 1 mole of N2 reacts with 3 moles of H2. Therefore, the number of moles of N2 required to react with 4.5 mol of H2 is:

moles of N2 = 4.5/3 = 1.5 mol

Now we can calculate the atomic mass of nitrogen:

mass of nitrogen = 42 g
number of moles of nitrogen = mass/molar mass
molar mass of nitrogen = mass/number of moles = 42/1.5 = 28 g/mol

The atomic mass of nitrogen is equal to its molar mass, so the answer is:

Answer: E (14 is the atomic mass of nitrogen)

If 42 G of Nitrogen Reacts Completely with 9 G