Question

1. how many moles of nh₃ are there in 2.80 grams n₂? (1st grams a to moles a using molar mass; 2nd moles a to moles b using balanced equation)

hint: grams n₂ (molar mass) → moles n₂ (balanced eq) → moles nh₃
mol nh₃ = mol nh₃ = 2.80g n₂ ×

1. how many grams of h₂ are there in 2.50 grams nh₃? 1st grams a to moles a using balanced eq; 2nd moles a to moles b using balanced eq; 3rd moles b to grams b using molar mass)

hint: grams nh₃ (molar mass) → moles nh₃ (balanced eq) → moles h₂ (molar mass) → grams h₂

Explanation:

Step1: Convert grams of N₂ to moles of N₂

The molar mass of N₂ is 28.02 g/mol. So, $n_{N_2}=\frac{2.80\ g}{28.02\ g/mol}\approx0.1\ mol$

Step2: Use balanced - equation to convert moles of N₂ to moles of NH₃

The balanced equation for the formation of NH₃ from N₂ and H₂ is $N_2 + 3H_2
ightarrow2NH_3$. The mole - ratio of N₂ to NH₃ is 1:2. So, $n_{NH_3}=0.1\ mol\times2 = 0.2\ mol$

Answer:

0.2 mol