Under the same conditions, are required?

Nitrogen reacts with powdered aluminum according to the reaction:
[tex]\[
2 \text{Al} (s) + \text{N}_2 (g) \longrightarrow 2 \text{AlN} (s)
\][/tex]

How many liters of [tex]\(\text{N}_2\)[/tex] gas, measured at 892 torr and [tex]\(95^{\circ} C\)[/tex], are required to completely react with 18.5 g of Al?



Answer :

Sure, let's solve this step-by-step:

1. Determine the moles of aluminum (Al):

- Given mass of aluminum ([tex]\( \text{Al} \)[/tex]) is 18.5 grams.
- The molar mass of aluminum ([tex]\( \text{Al} \)[/tex]) is 26.98 grams per mole.

We find the number of moles of aluminum using the formula:
[tex]\[ \text{moles of Al} = \frac{\text{mass of Al}}{\text{molar mass of Al}} \][/tex]
[tex]\[ \text{moles of Al} = \frac{18.5 \text{ g}}{26.98 \text{ g/mol}} = 0.6856931060044478 \text{ mol} \][/tex]

2. Determine the moles of nitrogen ([tex]\( \text{N}_2 \)[/tex]) required:

- According to the balanced chemical reaction:
[tex]\[ 2 \text{Al} + \text{N}_2 \rightarrow 2 \text{AlN} \][/tex]
2 moles of aluminum ([tex]\( \text{Al} \)[/tex]) react with 1 mole of nitrogen ([tex]\( \text{N}_2 \)[/tex]).

Therefore, the moles of [tex]\( \text{N}_2 \)[/tex] required will be half the moles of [tex]\( \text{Al} \)[/tex]:
[tex]\[ \text{moles of N}_2 = \frac{\text{moles of Al}}{2} = \frac{0.6856931060044478 \text{ mol}}{2} = 0.3428465530022239 \text{ mol} \][/tex]

3. Calculate the volume of [tex]\( \text{N}_2 \)[/tex] gas using the Ideal Gas Law:

The ideal gas law is given by:
[tex]\[ PV = nRT \][/tex]
rearranged to solve for volume ([tex]\( V \)[/tex]):
[tex]\[ V = \frac{nRT}{P} \][/tex]

Where:
- [tex]\( P \)[/tex] is the pressure in atmospheres (atm),
- Given pressure is 892 torr.
- Convert torr to atm: [tex]\( 1 \text{ atm} = 760 \text{ torr} \)[/tex]
[tex]\[ \text{Pressure in atm} = \frac{892 \text{ torr}}{760 \text{ torr/atm}} = 1.1736842105263158 \text{ atm} \][/tex]
- [tex]\( n \)[/tex] is the number of moles of gas ([tex]\( 0.3428465530022239 \text{ mol} \)[/tex]),
- [tex]\( R \)[/tex] is the ideal gas constant ([tex]\( 0.0821 \text{ L.atm/(mol.K)} \)[/tex]),
- [tex]\( T \)[/tex] is the temperature in Kelvin,
- Given temperature is [tex]\( 95^\circ \text{C} \)[/tex],
- Convert to Kelvin: [tex]\( T = 95 + 273.15 = 368.15 \text{ K} \)[/tex].

Plugging in these values:
[tex]\[ V = \frac{(0.3428465530022239 \text{ mol}) (0.0821 \text{ L.atm/(mol.K)}) (368.15 \text{ K}) }{1.1736842105263158 \text{ atm}} \][/tex]

Calculating this:
[tex]\[ V = 8.829101046864142 \text{ Liters} \][/tex]

So, [tex]\( 8.829 \)[/tex] liters of [tex]\( \text{N}_2 \)[/tex] gas, measured at 892 torr and [tex]\( 95^\circ \text{C} \)[/tex], are required to completely react with 18.5 grams of aluminum.