Answered

how many grams of aluminum sulfide can form from the reaction 9.00 g of aluminum with 8.00 g of sulfur



Answer :

2Al + 3S ---> Al₂S₃

1 mole of Al = 27g
1 mole of S = 32g
1 mole of Al₂S₃ = 150g

according to the reaction:
2*27g Al ------------------ 3*32g S
9g Al---------------------------- x g S
x = 16g S >> s, alluminium is excess


according to the reaction:
3*32g S----------------------- 150g Al₂S₃
8g S------------------------------ x Al₂S₃
x = 12,5g Al₂S₃

Answer : The mass of aluminum sulfide form from the reaction can be 12.5 grams.

Solution : Given,

Mass of Al = 9.00 g

Mass of [tex]S_8[/tex] = 8.00 g

Molar mass of Al = 27 g/mole

Molar mass of [tex]S_8[/tex] = 256 g/mole

Molar mass of [tex]Al_2S_3[/tex] = 150.2 g/mole

First we have to calculate the moles of Al and [tex]S_8[/tex].

[tex]\text{ Moles of }Al=\frac{\text{ Mass of }Al}{\text{ Molar mass of }Al}=\frac{9.00g}{27g/mole}=0.333moles[/tex]

[tex]\text{ Moles of }S_8=\frac{\text{ Mass of }S_8}{\text{ Molar mass of }S_8}=\frac{8.00g}{256g/mole}=0.0312moles[/tex]

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

[tex]16Al(s)+3S_8(s)\rightarrow 8Al_2S_3(s)[/tex]

From the balanced reaction we conclude that

As, 3 mole of [tex]S_8[/tex] react with 16 mole of [tex]Al[/tex]

So, 0.0312 moles of [tex]S_8[/tex] react with [tex]\frac{0.0312}{3}\times 16=0.166[/tex] moles of [tex]Al[/tex]

From this we conclude that, [tex]Al[/tex] is an excess reagent because the given moles are greater than the required moles and [tex]S_8[/tex] is a limiting reagent and it limits the formation of product.

Now we have to calculate the moles of [tex]Al_2S_3[/tex]

From the reaction, we conclude that

As, 3 mole of [tex]S_8[/tex] react to give 8 mole of [tex]Al_2S_3[/tex]

So, 0.0312 moles of [tex]S_8[/tex] react to give [tex]\frac{0.0312}{3}\times 8=0.0832[/tex] moles of [tex]Al_2S_3[/tex]

Now we have to calculate the mass of [tex]Al_2S_3[/tex]

[tex]\text{ Mass of }Al_2S_3=\text{ Moles of }Al_2S_3\times \text{ Molar mass of }Al_2S_3[/tex]

[tex]\text{ Mass of }Al_2S_3=(0.0832moles)\times (150.2g/mole)=12.5g[/tex]

Therefore, the mass of aluminum sulfide form from the reaction can be 12.5 grams.