To determine how many grams of the excess reagent remain after the reaction, we can follow these steps:

Step 1: Write the balanced chemical equation for the reaction.

The reaction between aluminum nitrite $(\text{Al(NO}_2)_3)$ and ammonium chloride $(\text{NH}_4\text{Cl})$ can be written as follows:

$\text{Al(NO}_2)_3 + 3 \text{NH}_4\text{Cl} \rightarrow \text{AlCl}_3 + 3 \text{N}_2 + 6 \text{H}_2\text{O}$

Step 2: Calculate the molar masses of the reactants.

• Aluminum nitrite (Al(NO$_2$)$_3$): $\text{Al} = 26.98 \, \text{g/mol}, \, \text{N} = 14.01 \, \text{g/mol}, \, \text{O} = 16.00 \, \text{g/mol}$ $\text{Molar mass of Al(NO}_2)_3 = 26.98 + 3(14.01 + 2 \times 16.00) = 26.98 + 3(46.01) = 165.01 \, \text{g/mol}$

• Ammonium chloride (NH$_4$Cl): $\text{N} = 14.01 \, \text{g/mol}, \, \text{H} = 1.008 \, \text{g/mol}, \, \text{Cl} = 35.45 \, \text{g/mol}$ $\text{Molar mass of NH}_4\text{Cl} = 14.01 + 4(1.008) + 35.45 = 53.49 \, \text{g/mol}$

Step 3: Convert the masses of reactants to moles.

• Moles of aluminum nitrite: $\frac{116.7 \, \text{g}}{165.01 \, \text{g/mol}} = 0.707 \, \text{mol}$

• Moles of ammonium chloride: $\frac{193.2 \, \text{g}}{53.49 \, \text{g/mol}} = 3.614 \, \text{mol}$

Step 4: Determine the limiting reagent.

From the balanced equation, 1 mole of Al(NO$_2$)$_3$ reacts with 3 moles of NH$_4$Cl. To react with 0.707 moles of Al(NO$_2$)$_3$, the required moles of NH$_4$Cl are: $0.707 \, \text{mol Al(NO}_2)_3 \times 3 = 2.121 \, \text{mol NH}_4\text{Cl}$

Since we have 3.614 moles of NH$_4$Cl, which is more than 2.121 moles, ammonium chloride is in excess, and aluminum nitrite is the limiting reagent.

Step 5: Calculate the amount of excess ammonium chloride remaining.

The amount of ammonium chloride reacted is 2.121 moles, so the remaining moles are: $3.614 - 2.121 = 1.493 \, \text{mol NH}_4\text{Cl}$

Step 6: Convert the remaining moles of ammonium chloride to grams.

$1.493 \, \text{mol} \times 53.49 \, \text{g/mol} = 79.88 \, \text{g}$

Final Answer:

There are 79.88 g of ammonium chloride remaining after the reaction.

Would you like further details or have any questions?

Here are 5 related questions:

1. How do you determine the limiting reagent in a chemical reaction?
2. What are the products formed in this reaction, and how are they derived from the reactants?
3. How do you calculate the theoretical yield of a product in a chemical reaction?
4. What is the significance of the stoichiometric ratio in a balanced chemical equation?
5. How would you calculate the percent yield of a reaction?

Tip: Always ensure the chemical equation is balanced before starting calculations for stoichiometry.