Question

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: Calculate moles of NH₃

$n_{NH_3}=\frac{2.50g}{17.03g/mol}$

Step2: Use mole - ratio from balanced equation

For $N_2 + 3H_2
ightarrow2NH_3$, mole - ratio of $H_2$ to $NH_3$ is 3:2. So $n_{H_2}=n_{NH_3}\times\frac{3}{2}$

Step3: Calculate mass of H₂

$m_{H_2}=n_{H_2}\times2.02g/mol$

Answer:

0.444 g H₂