Question

Nitrogen reacts with a metal to form a compound in which there are three atoms of the metal for each atom of nitrogen. If 1.486

g of the metal reacts with 1.000 g of nitrogen, what is the calculated atomic mass of the metal?
Use your calculated atomic mass to identify the metal. (For your answer, input the proper chemical symbol for element X.)

Answer 1

`\boxed{\text{6.937 u; X = Li}}`

Step-by-step explanation:

1. Write the unbalanced equation

X + N₂ ⟶ X₃N

2. Balance the equation and gather all the data.

MM: 28.01

6X + N₂ ⟶ 2X₃N

m/g 1.486 1.000

3. Calculate the moles of N₂

`\text{Moles of N}_(2) = \text{1.000 g N}_(2) * \frac{\text{1 mol N}_(2)}{\text{28.01 g N}_(2)} = \text{0.035 70 mol N}_(2)`

4. Calculate the moles of X

The molar ratio is 6 mol X: 1 mol N₂

`\text{Moles of X} = \text{0.035 70 mol N}_(2) * \frac{\text{6 mol X}}{\text{1 mol N}_(2)} = \text{0.2142 mol X}`

5. Calculate the molar mass of X

`\text{Molar mass} = \frac{\text{mass}}{\text{moles}} = \frac{\text{1.486 g}}{\text{0.2142 mol}} = \text{6.937 g/mol}\\\text{The molar mass of X is 6.937 g/mol, so the atomic mass $\boxed{\textbf{6.937 u}}$}`

6. Identify X.

`\text{X has an atomic mass of 6.937 u, so $\boxed{\textbf{X = Li}}$ (at. mass 6.94 u)}`